[ELF] Wrap things in `namespace lld { namespace elf {`, NFC

[MaskRay]

Summary

This makes it clear ELF/**/*.cpp files define things in the lld::elf
namespace and simplifies elf::foo to foo.

[MaskRay]

Add reviewers

[grimar]

LG. Lets see what other people think.

[ruiu]

I think that somewhere in the Coding Style Guideline, it is recommended to keep namespace {} as narrow as possible. This is why I chose this style in the first place. Has that changed?

[atanasyan]

LGTM

[MaskRay]

In D68323#1690943, @ruiu wrote:

I think that somewhere in the Coding Style Guideline, it is recommended to keep namespace {} as narrow as possible. This is why I chose this style in the first place. Has that changed?

I don't know the history but https://llvm.org/docs/CodingStandards.html#id56 gives an example that does this:

namespace llvm {
namespace knowledge {
...

[MaskRay]

@ruiu Are you happy with this change?

[ruiu]

Yeah, I'm fine with quoting the entire file with the namespaces, but I'm not entirely happy about adding endian:: to read32. Looks like the problem is that we use the same name for two functions. Can you just rename one to avoid the name collision? Does that make the code look simpler?

[MaskRay]

In D68323#1694029, @ruiu wrote:

Yeah, I'm fine with quoting the entire file with the namespaces, but I'm not entirely happy about adding endian:: to read32. Looks like the problem is that we use the same name for two functions. Can you just rename one to avoid the name collision? Does that make the code look simpler?

Adding endian:: is due to the rule of unqualified name lookup. Renaming either family of functions below will cause the change of hundreds of call sites changes.

llvm::support::endian::write32 and its friends
lld::elf::write32 and its friends

llvm::support::endian::* is used in very few files. And as this patch suggests, only Mips.cpp needs endian::*. I think this change clarifies things without making code more complex.

[ruiu]

How about always using elf::write32 instead of endian::write32<E>?

[MaskRay]

In D68323#1694050, @ruiu wrote:

How about always using elf::write32 instead of endian::write32<E>?

lld::elf::* are more commonly used in lld. This will end up with a lot of qualified write32 read16 calls. I think we should reduce the number of using namespace llvm::support::endian;.

[ruiu]

In D68323#1694079, @MaskRay wrote:

In D68323#1694050, @ruiu wrote:

How about always using elf::write32 instead of endian::write32<E>?

lld::elf::* are more commonly used in lld. This will end up with a lot of qualified write32 read16 calls. I think we should reduce the number of using namespace llvm::support::endian;.

I mean we can replace all occurrences of endian::write32<E>() with write32(). It looks like lld still compiles after I run the following command to replace them.

sed -i 's/write32<.>/write32/g' lld/ELF/Arch/Mips.cpp

[MaskRay]

In D68323#1694096, @ruiu wrote:

In D68323#1694079, @MaskRay wrote:

In D68323#1694050, @ruiu wrote:

How about always using elf::write32 instead of endian::write32<E>?

lld::elf::* are more commonly used in lld. This will end up with a lot of qualified write32 read16 calls. I think we should reduce the number of using namespace llvm::support::endian;.

I mean we can replace all occurrences of endian::write32<E>() with write32(). It looks like lld still compiles after I run the following command to replace them.

sed -i 's/write32<.>/write32/g' lld/ELF/Arch/Mips.cpp

This will make the generated code slightly worse because the implementation tests config->endianness. llvm::support::endian::write16(p, v, config->endianness);

Personally I prefer keeping the templated version, though I don't mind changing it if you are strong about this or @atanasyan is fine with lld::elf::* functions.

[ruiu]

In D68323#1694097, @MaskRay wrote:

In D68323#1694096, @ruiu wrote:

In D68323#1694079, @MaskRay wrote:

In D68323#1694050, @ruiu wrote:

How about always using elf::write32 instead of endian::write32<E>?

lld::elf::* are more commonly used in lld. This will end up with a lot of qualified write32 read16 calls. I think we should reduce the number of using namespace llvm::support::endian;.

I mean we can replace all occurrences of endian::write32<E>() with write32(). It looks like lld still compiles after I run the following command to replace them.

sed -i 's/write32<.>/write32/g' lld/ELF/Arch/Mips.cpp

This will make the generated code slightly worse because the implementation tests config->endianness. llvm::support::endian::write16(p, v, config->endianness);

Personally I prefer keeping the templated version, though I don't mind changing it if you are strong about this or @atanasyan is fine with lld::elf::* functions.

I originally preferred the template version of write32 for the exact same reason, but I now prefer non-template write32 because it doesn't seem slow at all, perhaps because the branch is highly predictable. Every time it actually branches to the same direction. So maybe the template version is just making the code too verbose?

[MaskRay]

Rebase on D68561

[ruiu]

LGTM

[MaskRay]

Update description. We don't change write* read* now

ELF/Arch/AArch64.cpp

 #include "Thunks.h"
 #include "lld/Common/ErrorHandler.h"
 #include "llvm/Object/ELF.h"
 #include "llvm/Support/Endian.h"
 
 using namespace llvm;
 using namespace llvm::support::endian;
 using namespace llvm::ELF;
-using namespace lld;
-using namespace lld::elf;
+
+namespace lld {
+namespace elf {
 
 // Page(Expr) is the page address of the expression Expr, defined
 // as (Expr & ~0xFFF). (This applies even if the machine page size
 // supported by the platform has a different value.)
-uint64_t elf::getAArch64Page(uint64_t expr) {
+uint64_t getAArch64Page(uint64_t expr) {
   return expr & ~static_cast<uint64_t>(0xFFF);
 }
 
 namespace {
 class AArch64 : public TargetInfo {
 public:
   AArch64();
   RelExpr getRelExpr(RelType type, const Symbol &s,
if (config->andFeatures & (GNU_PROPERTY_AARCH64_FEATURE_1_BTI |
                              GNU_PROPERTY_AARCH64_FEATURE_1_PAC)) {
     static AArch64BtiPac t;
     return &t;
   }
   static AArch64 t;
   return &t;
 }
 
-TargetInfo *elf::getAArch64TargetInfo() { return getTargetInfo(); }
+TargetInfo *getAArch64TargetInfo() { return getTargetInfo(); }
+
+} // namespace elf
+} // namespace lld

ELF/Arch/AMDGPU.cpp

 #include "lld/Common/ErrorHandler.h"
 #include "llvm/Object/ELF.h"
 #include "llvm/Support/Endian.h"
 
 using namespace llvm;
 using namespace llvm::object;
 using namespace llvm::support::endian;
 using namespace llvm::ELF;
-using namespace lld;
-using namespace lld::elf;
+
+namespace lld {
+namespace elf {
 
 namespace {
 class AMDGPU final : public TargetInfo {
 public:
   AMDGPU();
   uint32_t calcEFlags() const override;
   void relocateOne(uint8_t *loc, RelType type, uint64_t val) const override;
   RelExpr getRelExpr(RelType type, const Symbol &s,

 }
 
 RelType AMDGPU::getDynRel(RelType type) const {
   if (type == R_AMDGPU_ABS64)
     return type;
   return R_AMDGPU_NONE;
 }
 
-TargetInfo *elf::getAMDGPUTargetInfo() {
+TargetInfo *getAMDGPUTargetInfo() {
   static AMDGPU target;
   return ⌖
 }
+
+} // namespace elf
+} // namespace lld

ELF/Arch/ARM.cpp

 #include "Thunks.h"
 #include "lld/Common/ErrorHandler.h"
 #include "llvm/Object/ELF.h"
 #include "llvm/Support/Endian.h"
 
 using namespace llvm;
 using namespace llvm::support::endian;
 using namespace llvm::ELF;
-using namespace lld;
-using namespace lld::elf;
+
+namespace lld {
+namespace elf {
 
 namespace {
 class ARM final : public TargetInfo {
 public:
   ARM();
   uint32_t calcEFlags() const override;
   RelExpr getRelExpr(RelType type, const Symbol &s,
                      const uint8_t *loc) const override;
case R_ARM_THM_MOVT_PREL: {
     return SignExtend64<16>(((hi & 0x000f) << 12) | // imm4
                             ((hi & 0x0400) << 1) |  // i
                             ((lo & 0x7000) >> 4) |  // imm3
                             (lo & 0x00ff));         // imm8
   }
   }
 }
 
-TargetInfo *elf::getARMTargetInfo() {
+TargetInfo *getARMTargetInfo() {
   static ARM target;
   return &target;
 }
+
+} // namespace elf
+} // namespace lld

ELF/Arch/AVR.cpp

 #include "lld/Common/ErrorHandler.h"
 #include "llvm/Object/ELF.h"
 #include "llvm/Support/Endian.h"
 
 using namespace llvm;
 using namespace llvm::object;
 using namespace llvm::support::endian;
 using namespace llvm::ELF;
-using namespace lld;
-using namespace lld::elf;
+
+namespace lld {
+namespace elf {
 
 namespace {
 class AVR final : public TargetInfo {
 public:
   AVR();
   RelExpr getRelExpr(RelType type, const Symbol &s,
                      const uint8_t *loc) const override;
   void relocateOne(uint8_t *loc, RelType type, uint64_t val) const override;
case R_AVR_CALL: {
     write16le(loc + 2, lo);
     break;
   }
   default:
     error(getErrorLocation(loc) + "unrecognized relocation " + toString(type));
   }
 }
 
-TargetInfo *elf::getAVRTargetInfo() {
+TargetInfo *getAVRTargetInfo() {
   static AVR target;
   return ⌖
 }
+
+} // namespace elf
+} // namespace lld

ELF/Arch/Hexagon.cpp

 #include "llvm/BinaryFormat/ELF.h"
 #include "llvm/Object/ELF.h"
 #include "llvm/Support/Endian.h"
 
 using namespace llvm;
 using namespace llvm::object;
 using namespace llvm::support::endian;
 using namespace llvm::ELF;
-using namespace lld;
-using namespace lld::elf;
+
+namespace lld {
+namespace elf {
 
 namespace {
 class Hexagon final : public TargetInfo {
 public:
   Hexagon();
   uint32_t calcEFlags() const override;
   RelExpr getRelExpr(RelType type, const Symbol &s,
                      const uint8_t *loc) const override;

 }
 
 RelType Hexagon::getDynRel(RelType type) const {
   if (type == R_HEX_32)
     return type;
   return R_HEX_NONE;
 }
 
-TargetInfo *elf::getHexagonTargetInfo() {
+TargetInfo *getHexagonTargetInfo() {
   static Hexagon target;
   return ⌖
 }
+
+} // namespace elf
+} // namespace lld

ELF/Arch/MSP430.cpp

 #include "lld/Common/ErrorHandler.h"
 #include "llvm/Object/ELF.h"
 #include "llvm/Support/Endian.h"
 
 using namespace llvm;
 using namespace llvm::object;
 using namespace llvm::support::endian;
 using namespace llvm::ELF;
-using namespace lld;
-using namespace lld::elf;
+
+namespace lld {
+namespace elf {
 
 namespace {
 class MSP430 final : public TargetInfo {
 public:
   MSP430();
   RelExpr getRelExpr(RelType type, const Symbol &s,
                      const uint8_t *loc) const override;
   void relocateOne(uint8_t *loc, RelType type, uint64_t val) const override;
case R_MSP430_10_PCREL: {
     write16le(loc, (read16le(loc) & 0xFC00) | (offset & 0x3FF));
     break;
   }
   default:
     error(getErrorLocation(loc) + "unrecognized relocation " + toString(type));
   }
 }
 
-TargetInfo *elf::getMSP430TargetInfo() {
+TargetInfo *getMSP430TargetInfo() {
   static MSP430 target;
   return ⌖
 }
+
+} // namespace elf
+} // namespace lld

ELF/Arch/Mips.cpp

 #include "Target.h"
 #include "Thunks.h"
 #include "lld/Common/ErrorHandler.h"
 #include "llvm/Object/ELF.h"
 #include "llvm/Support/Endian.h"
 
 using namespace llvm;
 using namespace llvm::object;
-using namespace llvm::support::endian;
 using namespace llvm::ELF;
-using namespace lld;
-using namespace lld::elf;
+
+namespace endian = llvm::support::endian;
+
+namespace lld {
+namespace elf {
 
 namespace {
 template <class ELFT> class MIPS final : public TargetInfo {
 public:
   MIPS();
   uint32_t calcEFlags() const override;
   RelExpr getRelExpr(RelType type, const Symbol &s,
                      const uint8_t *loc) const override;
template <class ELFT> MIPS<ELFT>::MIPS() {
   pltEntrySize = 16;
   pltHeaderSize = 32;
   copyRel = R_MIPS_COPY;
   noneRel = R_MIPS_NONE;
   pltRel = R_MIPS_JUMP_SLOT;
   needsThunks = true;
 
   // Set `sigrie 1` as a trap instruction.
-  write32(trapInstr.data(), 0x04170001);
+  endian::write32<ELFT::TargetEndianness>(trapInstr.data(), 0x04170001);
 
   if (ELFT::Is64Bits) {
     relativeRel = (R_MIPS_64 << 8) | R_MIPS_REL32;
     symbolicRel = R_MIPS_64;
     tlsGotRel = R_MIPS_TLS_TPREL64;
     tlsModuleIndexRel = R_MIPS_TLS_DTPMOD64;
     tlsOffsetRel = R_MIPS_TLS_DTPREL64;
   } else {
template <class ELFT> RelType MIPS<ELFT>::getDynRel(RelType type) const {
   return R_MIPS_NONE;
 }
 
 template <class ELFT>
 void MIPS<ELFT>::writeGotPlt(uint8_t *buf, const Symbol &) const {
   uint64_t va = in.plt->getVA();
   if (isMicroMips())
     va |= 1;
-  write32<ELFT::TargetEndianness>(buf, va);
+  endian::write32<ELFT::TargetEndianness>(buf, va);
 }
 
 template <endianness E> static uint32_t readShuffle(const uint8_t *loc) {
   // The major opcode of a microMIPS instruction needs to appear
   // in the first 16-bit word (lowest address) for efficient hardware
   // decode so that it knows if the instruction is 16-bit or 32-bit
   // as early as possible. To do so, little-endian binaries keep 16-bit
   // words in a big-endian order. That is why we have to swap these
   // words to get a correct value.
-  uint32_t v = read32<E>(loc);
+  uint32_t v = endian::read32<E>(loc);
   if (E == support::little)
     return (v << 16) | (v >> 16);
   return v;
 }
 
 template <endianness E>
 static void writeValue(uint8_t *loc, uint64_t v, uint8_t bitsSize,
                        uint8_t shift) {
-  uint32_t instr = read32<E>(loc);
+  uint32_t instr = endian::read32<E>(loc);
   uint32_t mask = 0xffffffff >> (32 - bitsSize);
   uint32_t data = (instr & ~mask) | ((v >> shift) & mask);
-  write32<E>(loc, data);
+  endian::write32<E>(loc, data);
 }
 
 template <endianness E>
 static void writeShuffleValue(uint8_t *loc, uint64_t v, uint8_t bitsSize,
                               uint8_t shift) {
   // See comments in readShuffle for purpose of this code.
   uint16_t *words = (uint16_t *)loc;
   if (E == support::little)
     std::swap(words[0], words[1]);
 
   writeValue<E>(loc, v, bitsSize, shift);
 
   if (E == support::little)
     std::swap(words[0], words[1]);
 }
 
 template <endianness E>
 static void writeMicroRelocation16(uint8_t *loc, uint64_t v, uint8_t bitsSize,
                                    uint8_t shift) {
-  uint16_t instr = read16<E>(loc);
+  uint16_t instr = endian::read16<E>(loc);
   uint16_t mask = 0xffff >> (16 - bitsSize);
   uint16_t data = (instr & ~mask) | ((v >> shift) & mask);
-  write16<E>(loc, data);
+  endian::write16<E>(loc, data);
 }
 
 template <class ELFT> void MIPS<ELFT>::writePltHeader(uint8_t *buf) const {
   const endianness e = ELFT::TargetEndianness;
   if (isMicroMips()) {
     uint64_t gotPlt = in.gotPlt->getVA();
     uint64_t plt = in.plt->getVA();
     // Overwrite trap instructions written by Writer::writeTrapInstr.
     memset(buf, 0, pltHeaderSize);
 
-    write16<e>(buf, isMipsR6() ? 0x7860 : 0x7980);  // addiupc v1, (GOTPLT) - .
-    write16<e>(buf + 4, 0xff23);    // lw      $25, 0($3)
-    write16<e>(buf + 8, 0x0535);    // subu16  $2,  $2, $3
-    write16<e>(buf + 10, 0x2525);   // srl16   $2,  $2, 2
-    write16<e>(buf + 12, 0x3302);   // addiu   $24, $2, -2
-    write16<e>(buf + 14, 0xfffe);
-    write16<e>(buf + 16, 0x0dff);   // move    $15, $31
+    endian::write16<e>(buf, isMipsR6() ? 0x7860
+                                       : 0x7980); // addiupc v1, (GOTPLT) - .
+    endian::write16<e>(buf + 4, 0xff23);          // lw      $25, 0($3)
+    endian::write16<e>(buf + 8, 0x0535);          // subu16  $2,  $2, $3
+    endian::write16<e>(buf + 10, 0x2525);         // srl16   $2,  $2, 2
+    endian::write16<e>(buf + 12, 0x3302);         // addiu   $24, $2, -2
+    endian::write16<e>(buf + 14, 0xfffe);
+    endian::write16<e>(buf + 16, 0x0dff); // move    $15, $31
     if (isMipsR6()) {
-      write16<e>(buf + 18, 0x0f83); // move    $28, $3
-      write16<e>(buf + 20, 0x472b); // jalrc   $25
-      write16<e>(buf + 22, 0x0c00); // nop
+      endian::write16<e>(buf + 18, 0x0f83); // move    $28, $3
+      endian::write16<e>(buf + 20, 0x472b); // jalrc   $25
+      endian::write16<e>(buf + 22, 0x0c00); // nop
       relocateOne(buf, R_MICROMIPS_PC19_S2, gotPlt - plt);
     } else {
-      write16<e>(buf + 18, 0x45f9); // jalrc   $25
-      write16<e>(buf + 20, 0x0f83); // move    $28, $3
-      write16<e>(buf + 22, 0x0c00); // nop
+      endian::write16<e>(buf + 18, 0x45f9); // jalrc   $25
+      endian::write16<e>(buf + 20, 0x0f83); // move    $28, $3
+      endian::write16<e>(buf + 22, 0x0c00); // nop
       relocateOne(buf, R_MICROMIPS_PC23_S2, gotPlt - plt);
     }
     return;
   }
 
   if (config->mipsN32Abi) {
-    write32<e>(buf, 0x3c0e0000);      // lui   $14, %hi(&GOTPLT[0])
-    write32<e>(buf + 4, 0x8dd90000);  // lw    $25, %lo(&GOTPLT[0])($14)
-    write32<e>(buf + 8, 0x25ce0000);  // addiu $14, $14, %lo(&GOTPLT[0])
-    write32<e>(buf + 12, 0x030ec023); // subu  $24, $24, $14
-    write32<e>(buf + 16, 0x03e07825); // move  $15, $31
-    write32<e>(buf + 20, 0x0018c082); // srl   $24, $24, 2
+    endian::write32<e>(buf, 0x3c0e0000);      // lui   $14, %hi(&GOTPLT[0])
+    endian::write32<e>(buf + 4, 0x8dd90000);  // lw    $25, %lo(&GOTPLT[0])($14)
+    endian::write32<e>(buf + 8, 0x25ce0000);  // addiu $14, $14, %lo(&GOTPLT[0])
+    endian::write32<e>(buf + 12, 0x030ec023); // subu  $24, $24, $14
+    endian::write32<e>(buf + 16, 0x03e07825); // move  $15, $31
+    endian::write32<e>(buf + 20, 0x0018c082); // srl   $24, $24, 2
   } else if (ELFT::Is64Bits) {
-    write32<e>(buf, 0x3c0e0000);      // lui   $14, %hi(&GOTPLT[0])
-    write32<e>(buf + 4, 0xddd90000);  // ld    $25, %lo(&GOTPLT[0])($14)
-    write32<e>(buf + 8, 0x25ce0000);  // addiu $14, $14, %lo(&GOTPLT[0])
-    write32<e>(buf + 12, 0x030ec023); // subu  $24, $24, $14
-    write32<e>(buf + 16, 0x03e07825); // move  $15, $31
-    write32<e>(buf + 20, 0x0018c0c2); // srl   $24, $24, 3
+    endian::write32<e>(buf, 0x3c0e0000);      // lui   $14, %hi(&GOTPLT[0])
+    endian::write32<e>(buf + 4, 0xddd90000);  // ld    $25, %lo(&GOTPLT[0])($14)
+    endian::write32<e>(buf + 8, 0x25ce0000);  // addiu $14, $14, %lo(&GOTPLT[0])
+    endian::write32<e>(buf + 12, 0x030ec023); // subu  $24, $24, $14
+    endian::write32<e>(buf + 16, 0x03e07825); // move  $15, $31
+    endian::write32<e>(buf + 20, 0x0018c0c2); // srl   $24, $24, 3
   } else {
-    write32<e>(buf, 0x3c1c0000);      // lui   $28, %hi(&GOTPLT[0])
-    write32<e>(buf + 4, 0x8f990000);  // lw    $25, %lo(&GOTPLT[0])($28)
-    write32<e>(buf + 8, 0x279c0000);  // addiu $28, $28, %lo(&GOTPLT[0])
-    write32<e>(buf + 12, 0x031cc023); // subu  $24, $24, $28
-    write32<e>(buf + 16, 0x03e07825); // move  $15, $31
-    write32<e>(buf + 20, 0x0018c082); // srl   $24, $24, 2
+    endian::write32<e>(buf, 0x3c1c0000);      // lui   $28, %hi(&GOTPLT[0])
+    endian::write32<e>(buf + 4, 0x8f990000);  // lw    $25, %lo(&GOTPLT[0])($28)
+    endian::write32<e>(buf + 8, 0x279c0000);  // addiu $28, $28, %lo(&GOTPLT[0])
+    endian::write32<e>(buf + 12, 0x031cc023); // subu  $24, $24, $28
+    endian::write32<e>(buf + 16, 0x03e07825); // move  $15, $31
+    endian::write32<e>(buf + 20, 0x0018c082); // srl   $24, $24, 2
   }
 
   uint32_t jalrInst = config->zHazardplt ? 0x0320fc09 : 0x0320f809;
-  write32<e>(buf + 24, jalrInst); // jalr.hb $25 or jalr $25
-  write32<e>(buf + 28, 0x2718fffe); // subu  $24, $24, 2
+  endian::write32<e>(buf + 24, jalrInst);   // jalr.hb $25 or jalr $25
+  endian::write32<e>(buf + 28, 0x2718fffe); // subu  $24, $24, 2
 
   uint64_t gotPlt = in.gotPlt->getVA();
   writeValue<e>(buf, gotPlt + 0x8000, 16, 16);
   writeValue<e>(buf + 4, gotPlt, 16, 0);
   writeValue<e>(buf + 8, gotPlt, 16, 0);
 }
 
 template <class ELFT>
 void MIPS<ELFT>::writePlt(uint8_t *buf, uint64_t gotPltEntryAddr,
                           uint64_t pltEntryAddr, int32_t index,
                           unsigned relOff) const {
   const endianness e = ELFT::TargetEndianness;
   if (isMicroMips()) {
     // Overwrite trap instructions written by Writer::writeTrapInstr.
     memset(buf, 0, pltEntrySize);
 
     if (isMipsR6()) {
-      write16<e>(buf, 0x7840);      // addiupc $2, (GOTPLT) - .
-      write16<e>(buf + 4, 0xff22);  // lw $25, 0($2)
-      write16<e>(buf + 8, 0x0f02);  // move $24, $2
-      write16<e>(buf + 10, 0x4723); // jrc $25 / jr16 $25
+      endian::write16<e>(buf, 0x7840);      // addiupc $2, (GOTPLT) - .
+      endian::write16<e>(buf + 4, 0xff22);  // lw $25, 0($2)
+      endian::write16<e>(buf + 8, 0x0f02);  // move $24, $2
+      endian::write16<e>(buf + 10, 0x4723); // jrc $25 / jr16 $25
       relocateOne(buf, R_MICROMIPS_PC19_S2, gotPltEntryAddr - pltEntryAddr);
     } else {
-      write16<e>(buf, 0x7900);      // addiupc $2, (GOTPLT) - .
-      write16<e>(buf + 4, 0xff22);  // lw $25, 0($2)
-      write16<e>(buf + 8, 0x4599);  // jrc $25 / jr16 $25
-      write16<e>(buf + 10, 0x0f02); // move $24, $2
+      endian::write16<e>(buf, 0x7900);      // addiupc $2, (GOTPLT) - .
+      endian::write16<e>(buf + 4, 0xff22);  // lw $25, 0($2)
+      endian::write16<e>(buf + 8, 0x4599);  // jrc $25 / jr16 $25
+      endian::write16<e>(buf + 10, 0x0f02); // move $24, $2
       relocateOne(buf, R_MICROMIPS_PC23_S2, gotPltEntryAddr - pltEntryAddr);
     }
     return;
   }
 
   uint32_t loadInst = ELFT::Is64Bits ? 0xddf90000 : 0x8df90000;
   uint32_t jrInst = isMipsR6() ? (config->zHazardplt ? 0x03200409 : 0x03200009)
                                : (config->zHazardplt ? 0x03200408 : 0x03200008);
   uint32_t addInst = ELFT::Is64Bits ? 0x65f80000 : 0x25f80000;
 
-  write32<e>(buf, 0x3c0f0000);     // lui   $15, %hi(.got.plt entry)
-  write32<e>(buf + 4, loadInst);   // l[wd] $25, %lo(.got.plt entry)($15)
-  write32<e>(buf + 8, jrInst);     // jr  $25 / jr.hb $25
-  write32<e>(buf + 12, addInst);   // [d]addiu $24, $15, %lo(.got.plt entry)
+  endian::write32<e>(buf, 0x3c0f0000);   // lui   $15, %hi(.got.plt entry)
+  endian::write32<e>(buf + 4, loadInst); // l[wd] $25, %lo(.got.plt entry)($15)
+  endian::write32<e>(buf + 8, jrInst);   // jr  $25 / jr.hb $25
+  endian::write32<e>(buf + 12,
+                     addInst); // [d]addiu $24, $15, %lo(.got.plt entry)
   writeValue<e>(buf, gotPltEntryAddr + 0x8000, 16, 16);
   writeValue<e>(buf + 4, gotPltEntryAddr, 16, 0);
   writeValue<e>(buf + 12, gotPltEntryAddr, 16, 0);
 }
 
 template <class ELFT>
 bool MIPS<ELFT>::needsThunk(RelExpr expr, RelType type, const InputFile *file,
                             uint64_t branchAddr, const Symbol &s) const {

 template <class ELFT>
 int64_t MIPS<ELFT>::getImplicitAddend(const uint8_t *buf, RelType type) const {
   const endianness e = ELFT::TargetEndianness;
   switch (type) {
   case R_MIPS_32:
   case R_MIPS_GPREL32:
   case R_MIPS_TLS_DTPREL32:
   case R_MIPS_TLS_TPREL32:
-    return SignExtend64<32>(read32<e>(buf));
+    return SignExtend64<32>(endian::read32<e>(buf));
   case R_MIPS_26:
     // FIXME (simon): If the relocation target symbol is not a PLT entry
     // we should use another expression for calculation:
     // ((A << 2) | (P & 0xf0000000)) >> 2
-    return SignExtend64<28>(read32<e>(buf) << 2);
+    return SignExtend64<28>(endian::read32<e>(buf) << 2);
   case R_MIPS_GOT16:
   case R_MIPS_HI16:
   case R_MIPS_PCHI16:
-    return SignExtend64<16>(read32<e>(buf)) << 16;
+    return SignExtend64<16>(endian::read32<e>(buf)) << 16;
   case R_MIPS_GPREL16:
   case R_MIPS_LO16:
   case R_MIPS_PCLO16:
   case R_MIPS_TLS_DTPREL_HI16:
   case R_MIPS_TLS_DTPREL_LO16:
   case R_MIPS_TLS_TPREL_HI16:
   case R_MIPS_TLS_TPREL_LO16:
-    return SignExtend64<16>(read32<e>(buf));
+    return SignExtend64<16>(endian::read32<e>(buf));
   case R_MICROMIPS_GOT16:
   case R_MICROMIPS_HI16:
     return SignExtend64<16>(readShuffle<e>(buf)) << 16;
   case R_MICROMIPS_GPREL16:
   case R_MICROMIPS_LO16:
   case R_MICROMIPS_TLS_DTPREL_HI16:
   case R_MICROMIPS_TLS_DTPREL_LO16:
   case R_MICROMIPS_TLS_TPREL_HI16:
   case R_MICROMIPS_TLS_TPREL_LO16:
     return SignExtend64<16>(readShuffle<e>(buf));
   case R_MICROMIPS_GPREL7_S2:
     return SignExtend64<9>(readShuffle<e>(buf) << 2);
   case R_MIPS_PC16:
-    return SignExtend64<18>(read32<e>(buf) << 2);
+    return SignExtend64<18>(endian::read32<e>(buf) << 2);
   case R_MIPS_PC19_S2:
-    return SignExtend64<21>(read32<e>(buf) << 2);
+    return SignExtend64<21>(endian::read32<e>(buf) << 2);
   case R_MIPS_PC21_S2:
-    return SignExtend64<23>(read32<e>(buf) << 2);
+    return SignExtend64<23>(endian::read32<e>(buf) << 2);
   case R_MIPS_PC26_S2:
-    return SignExtend64<28>(read32<e>(buf) << 2);
+    return SignExtend64<28>(endian::read32<e>(buf) << 2);
   case R_MIPS_PC32:
-    return SignExtend64<32>(read32<e>(buf));
+    return SignExtend64<32>(endian::read32<e>(buf));
   case R_MICROMIPS_26_S1:
     return SignExtend64<27>(readShuffle<e>(buf) << 1);
   case R_MICROMIPS_PC7_S1:
-    return SignExtend64<8>(read16<e>(buf) << 1);
+    return SignExtend64<8>(endian::read16<e>(buf) << 1);
   case R_MICROMIPS_PC10_S1:
-    return SignExtend64<11>(read16<e>(buf) << 1);
+    return SignExtend64<11>(endian::read16<e>(buf) << 1);
   case R_MICROMIPS_PC16_S1:
     return SignExtend64<17>(readShuffle<e>(buf) << 1);
   case R_MICROMIPS_PC18_S3:
     return SignExtend64<21>(readShuffle<e>(buf) << 3);
   case R_MICROMIPS_PC19_S2:
     return SignExtend64<21>(readShuffle<e>(buf) << 2);
   case R_MICROMIPS_PC21_S1:
     return SignExtend64<22>(readShuffle<e>(buf) << 1);
static uint64_t fixupCrossModeJump(uint8_t *loc, RelType type, uint64_t val) {
   bool isMicroTgt = val & 0x1;
   bool isCrossJump = (isMicroTgt && isBranchReloc(type)) ||
                      (!isMicroTgt && isMicroBranchReloc(type));
   if (!isCrossJump)
     return val;
 
   switch (type) {
   case R_MIPS_26: {
-    uint32_t inst = read32<e>(loc) >> 26;
+    uint32_t inst = endian::read32<e>(loc) >> 26;
     if (inst == 0x3 || inst == 0x1d) { // JAL or JALX
       writeValue<e>(loc, 0x1d << 26, 32, 0);
       return val;
     }
     break;
   }
   case R_MICROMIPS_26_S1: {
     uint32_t inst = readShuffle<e>(loc) >> 26;
if (type == R_MIPS_TLS_DTPREL_HI16 || type == R_MIPS_TLS_DTPREL_LO16 ||
     val -= 0x8000;
   }
 
   switch (type) {
   case R_MIPS_32:
   case R_MIPS_GPREL32:
   case R_MIPS_TLS_DTPREL32:
   case R_MIPS_TLS_TPREL32:
-    write32<e>(loc, val);
+    endian::write32<e>(loc, val);
     break;
   case R_MIPS_64:
   case R_MIPS_TLS_DTPREL64:
   case R_MIPS_TLS_TPREL64:
-    write64<e>(loc, val);
+    endian::write64<e>(loc, val);
     break;
   case R_MIPS_26:
     writeValue<e>(loc, val, 26, 2);
     break;
   case R_MIPS_GOT16:
     // The R_MIPS_GOT16 relocation's value in "relocatable" linking mode
     // is updated addend (not a GOT index). In that case write high 16 bits
     // to store a correct addend value.
void MIPS<ELFT>::relocateOne(uint8_t *loc, RelType type, uint64_t val) const {
   case R_MIPS_HIGHEST:
     writeValue<e>(loc, val + 0x800080008000, 16, 48);
     break;
   case R_MIPS_JALR:
     val -= 4;
     // Replace jalr/jr instructions by bal/b if the target
     // offset fits into the 18-bit range.
     if (isInt<18>(val)) {
-      switch (read32<e>(loc)) {
+      switch (endian::read32<e>(loc)) {
       case 0x0320f809:  // jalr $25 => bal sym
-        write32<e>(loc, 0x04110000 | ((val >> 2) & 0xffff));
+        endian::write32<e>(loc, 0x04110000 | ((val >> 2) & 0xffff));
         break;
       case 0x03200008:  // jr $25 => b sym
-        write32<e>(loc, 0x10000000 | ((val >> 2) & 0xffff));
+        endian::write32<e>(loc, 0x10000000 | ((val >> 2) & 0xffff));
         break;
       }
     }
     break;
   case R_MICROMIPS_JALR:
     // Ignore this optimization relocation for now
     break;
   case R_MIPS_PC16:

 }
 
 template <class ELFT> bool MIPS<ELFT>::usesOnlyLowPageBits(RelType type) const {
   return type == R_MIPS_LO16 || type == R_MIPS_GOT_OFST ||
          type == R_MICROMIPS_LO16;
 }
 
 // Return true if the symbol is a PIC function.
-template <class ELFT> bool elf::isMipsPIC(const Defined *sym) {
+template <class ELFT> bool isMipsPIC(const Defined *sym) {
   if (!sym->isFunc())
     return false;
 
   if (sym->stOther & STO_MIPS_PIC)
     return true;
 
   if (!sym->section)
     return false;
 
   ObjFile<ELFT> *file =
       cast<InputSectionBase>(sym->section)->template getFile<ELFT>();
   if (!file)
     return false;
 
   return file->getObj().getHeader()->e_flags & EF_MIPS_PIC;
 }
 
-template <class ELFT> TargetInfo *elf::getMipsTargetInfo() {
+template <class ELFT> TargetInfo *getMipsTargetInfo() {
   static MIPS<ELFT> target;
   return &target;
 }
 
-template TargetInfo *elf::getMipsTargetInfo<ELF32LE>();
-template TargetInfo *elf::getMipsTargetInfo<ELF32BE>();
-template TargetInfo *elf::getMipsTargetInfo<ELF64LE>();
-template TargetInfo *elf::getMipsTargetInfo<ELF64BE>();
-
-template bool elf::isMipsPIC<ELF32LE>(const Defined *);
-template bool elf::isMipsPIC<ELF32BE>(const Defined *);
-template bool elf::isMipsPIC<ELF64LE>(const Defined *);
-template bool elf::isMipsPIC<ELF64BE>(const Defined *);
+template TargetInfo *getMipsTargetInfo<ELF32LE>();
+template TargetInfo *getMipsTargetInfo<ELF32BE>();
+template TargetInfo *getMipsTargetInfo<ELF64LE>();
+template TargetInfo *getMipsTargetInfo<ELF64BE>();
+
+template bool isMipsPIC<ELF32LE>(const Defined *);
+template bool isMipsPIC<ELF32BE>(const Defined *);
+template bool isMipsPIC<ELF64LE>(const Defined *);
+template bool isMipsPIC<ELF64BE>(const Defined *);
+
+} // namespace elf
+} // namespace lld

ELF/Arch/MipsArchTree.cpp

 #include "llvm/BinaryFormat/ELF.h"
 #include "llvm/Object/ELF.h"
 #include "llvm/Support/MipsABIFlags.h"
 
 using namespace llvm;
 using namespace llvm::object;
 using namespace llvm::ELF;
 
-using namespace lld;
-using namespace lld::elf;
+namespace lld {
+namespace elf {
 
 namespace {
 struct ArchTreeEdge {
   uint32_t child;
   uint32_t parent;
 };
 
 struct FileFlags {
if (!isArchMatched(ret, newFlags)) {
             getFullArchName(newFlags));
       return 0;
     }
     ret = newFlags;
   }
   return ret;
 }
 
-template <class ELFT> uint32_t elf::calcMipsEFlags() {
+template <class ELFT> uint32_t calcMipsEFlags() {
   std::vector<FileFlags> v;
   for (InputFile *f : objectFiles)
     v.push_back({f, cast<ObjFile<ELFT>>(f)->getObj().getHeader()->e_flags});
   if (v.empty()) {
     // If we don't have any input files, we'll have to rely on the information
     // we can derive from emulation information, since this at least gets us
     // ABI.
     if (config->emulation.empty() || config->is64)
case Mips::Val_GNU_MIPS_ABI_FP_64:
     return "-mgp32 -mfp64";
   case Mips::Val_GNU_MIPS_ABI_FP_64A:
     return "-mgp32 -mfp64 -mno-odd-spreg";
   default:
     return "unknown";
   }
 }
 
-uint8_t elf::getMipsFpAbiFlag(uint8_t oldFlag, uint8_t newFlag,
-                              StringRef fileName) {
+uint8_t getMipsFpAbiFlag(uint8_t oldFlag, uint8_t newFlag, StringRef fileName) {
   if (compareMipsFpAbi(newFlag, oldFlag) >= 0)
     return newFlag;
   if (compareMipsFpAbi(oldFlag, newFlag) < 0)
     error(fileName + ": floating point ABI '" + getMipsFpAbiName(newFlag) +
           "' is incompatible with target floating point ABI '" +
           getMipsFpAbiName(oldFlag) + "'");
   return oldFlag;
 }
 
 template <class ELFT> static bool isN32Abi(const InputFile *f) {
   if (auto *ef = dyn_cast<ELFFileBase>(f))
     return ef->template getObj<ELFT>().getHeader()->e_flags & EF_MIPS_ABI2;
   return false;
 }
 
-bool elf::isMipsN32Abi(const InputFile *f) {
+bool isMipsN32Abi(const InputFile *f) {
   switch (config->ekind) {
   case ELF32LEKind:
     return isN32Abi<ELF32LE>(f);
   case ELF32BEKind:
     return isN32Abi<ELF32BE>(f);
   case ELF64LEKind:
     return isN32Abi<ELF64LE>(f);
   case ELF64BEKind:
     return isN32Abi<ELF64BE>(f);
   default:
     llvm_unreachable("unknown Config->EKind");
   }
 }
 
-bool elf::isMicroMips() { return config->eflags & EF_MIPS_MICROMIPS; }
+bool isMicroMips() { return config->eflags & EF_MIPS_MICROMIPS; }
 
-bool elf::isMipsR6() {
+bool isMipsR6() {
   uint32_t arch = config->eflags & EF_MIPS_ARCH;
   return arch == EF_MIPS_ARCH_32R6 || arch == EF_MIPS_ARCH_64R6;
 }
 
-template uint32_t elf::calcMipsEFlags<ELF32LE>();
-template uint32_t elf::calcMipsEFlags<ELF32BE>();
-template uint32_t elf::calcMipsEFlags<ELF64LE>();
-template uint32_t elf::calcMipsEFlags<ELF64BE>();
+template uint32_t calcMipsEFlags<ELF32LE>();
+template uint32_t calcMipsEFlags<ELF32BE>();
+template uint32_t calcMipsEFlags<ELF64LE>();
+template uint32_t calcMipsEFlags<ELF64BE>();
+
+} // namespace elf
+} // namespace lld

ELF/Arch/PPC.cpp

 #include "SyntheticSections.h"
 #include "Target.h"
 #include "lld/Common/ErrorHandler.h"
 #include "llvm/Support/Endian.h"
 
 using namespace llvm;
 using namespace llvm::support::endian;
 using namespace llvm::ELF;
-using namespace lld;
-using namespace lld::elf;
+
+namespace lld {
+namespace elf {
 
 namespace {
 class PPC final : public TargetInfo {
 public:
   PPC();
   RelExpr getRelExpr(RelType type, const Symbol &s,
                      const uint8_t *loc) const override;
   RelType getDynRel(RelType type) const override;

 static uint32_t readFromHalf16(const uint8_t *loc) {
   return read32(config->isLE ? loc : loc - 2);
 }
 
 static void writeFromHalf16(uint8_t *loc, uint32_t insn) {
   write32(config->isLE ? loc : loc - 2, insn);
 }
 
-void elf::writePPC32GlinkSection(uint8_t *buf, size_t numEntries) {
+void writePPC32GlinkSection(uint8_t *buf, size_t numEntries) {
   // On PPC Secure PLT ABI, bl foo@plt jumps to a call stub, which loads an
   // absolute address from a specific .plt slot (usually called .got.plt on
   // other targets) and jumps there.
   //
   // a) With immediate binding (BIND_NOW), the .plt entry is resolved at load
   // time. The .glink section is not used.
   // b) With lazy binding, the .plt entry points to a `b PLTresolve`
   // instruction in .glink, filled in by PPC::writeGotPlt().
case R_PPC_TLS: {
     write32(loc, (dFormOp << 26) | (insn & 0x03ff0000) | lo(val));
     break;
   }
   default:
     llvm_unreachable("unsupported relocation for TLS IE to LE relaxation");
   }
 }
 
-TargetInfo *elf::getPPCTargetInfo() {
+TargetInfo *getPPCTargetInfo() {
   static PPC target;
   return &target;
 }
+
+} // namespace elf
+} // namespace lld

ELF/Arch/PPC64.cpp

 #include "Target.h"
 #include "lld/Common/ErrorHandler.h"
 #include "llvm/Support/Endian.h"
 
 using namespace llvm;
 using namespace llvm::object;
 using namespace llvm::support::endian;
 using namespace llvm::ELF;
-using namespace lld;
-using namespace lld::elf;
+
+namespace lld {
+namespace elf {
 
 static uint64_t ppc64TocOffset = 0x8000;
 static uint64_t dynamicThreadPointerOffset = 0x8000;
 
 // The instruction encoding of bits 21-30 from the ISA for the Xform and Dform
 // instructions that can be used as part of the initial exec TLS sequence.
 enum XFormOpcd {
   LBZX = 87,
enum DFormOpcd {
   STW = 36,
   STWU = 37,
   STFSU = 53,
   STFDU = 55,
   STD = 62,
   ADDI = 14
 };
 
-uint64_t elf::getPPC64TocBase() {
+uint64_t getPPC64TocBase() {
   // The TOC consists of sections .got, .toc, .tocbss, .plt in that order. The
   // TOC starts where the first of these sections starts. We always create a
   // .got when we see a relocation that uses it, so for us the start is always
   // the .got.
   uint64_t tocVA = in.got->getVA();
 
   // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000
   // thus permitting a full 64 Kbytes segment. Note that the glibc startup
   // code (crt1.o) assumes that you can get from the TOC base to the
   // start of the .toc section with only a single (signed) 16-bit relocation.
   return tocVA + ppc64TocOffset;
 }
 
-unsigned elf::getPPC64GlobalEntryToLocalEntryOffset(uint8_t stOther) {
+unsigned getPPC64GlobalEntryToLocalEntryOffset(uint8_t stOther) {
   // The offset is encoded into the 3 most significant bits of the st_other
   // field, with some special values described in section 3.4.1 of the ABI:
   // 0   --> Zero offset between the GEP and LEP, and the function does NOT use
   //         the TOC pointer (r2). r2 will hold the same value on returning from
   //         the function as it did on entering the function.
   // 1   --> Zero offset between the GEP and LEP, and r2 should be treated as a
   //         caller-saved register for all callers.
   // 2-6 --> The  binary logarithm of the offset eg:
   //         2 --> 2^2 = 4 bytes -->  1 instruction.
   //         6 --> 2^6 = 64 bytes --> 16 instructions.
   // 7   --> Reserved.
   uint8_t gepToLep = (stOther >> 5) & 7;
   if (gepToLep < 2)
     return 0;
 
   // The value encoded in the st_other bits is the
   // log-base-2(offset).
   if (gepToLep < 7)
     return 1 << gepToLep;
 
   error("reserved value of 7 in the 3 most-significant-bits of st_other");
   return 0;
 }
 
-bool elf::isPPC64SmallCodeModelTocReloc(RelType type) {
+bool isPPC64SmallCodeModelTocReloc(RelType type) {
   // The only small code model relocations that access the .toc section.
   return type == R_PPC64_TOC16 || type == R_PPC64_TOC16_DS;
 }
 
 // Find the R_PPC64_ADDR64 in .rela.toc with matching offset.
 template <typename ELFT>
 static std::pair<Defined *, int64_t>
 getRelaTocSymAndAddend(InputSectionBase *tocSec, uint64_t offset) {

 // offset from the toc base, the address of var can be computed by adding an
 // offset to the toc base, saving a load.
 //
 //   addis 3,2,var@toc@ha     # this may be relaxed to a nop,
 //   addi  3,3,var@toc@l      # then this becomes addi 3,2,var@toc
 //   ld/lwa 3, 0(3)           # load the value from the address
 //
 // Returns true if the relaxation is performed.
-bool elf::tryRelaxPPC64TocIndirection(RelType type, const Relocation &rel,
-                                      uint8_t *bufLoc) {
+bool tryRelaxPPC64TocIndirection(RelType type, const Relocation &rel,
   assert(config->tocOptimize);
   if (rel.addend < 0)
     return false;
 
   // If the symbol is not the .toc section, this isn't a toc-indirection.
   Defined *defSym = dyn_cast<Defined>(rel.sym);
   if (!defSym || !defSym->isSection() || defSym->section->name != ".toc")
     return false;
void PPC64::relaxTlsLdToLe(uint8_t *loc, RelType type, uint64_t val) const {
   case R_PPC64_DTPREL16_LO_DS:
     relocateOne(loc, type, val);
     break;
   default:
     llvm_unreachable("unsupported relocation for TLS LD to LE relaxation");
   }
 }
 
-unsigned elf::getPPCDFormOp(unsigned secondaryOp) {
+unsigned getPPCDFormOp(unsigned secondaryOp) {
   switch (secondaryOp) {
   case LBZX:
     return LBZ;
   case LHZX:
     return LHZ;
   case LWZX:
     return LWZ;
   case LDX:
if (hiImm) {
     // addi r12, r1, imm
     write32(loc + 4, (0x39810000) | (uint16_t)loImm);
     write32(loc + 8, 0x60000000);
   }
 
   return true;
 }
 
-TargetInfo *elf::getPPC64TargetInfo() {
+TargetInfo *getPPC64TargetInfo() {
   static PPC64 target;
   return &target;
 }
+
+} // namespace elf
+} // namespace lld

ELF/Arch/RISCV.cpp

 //===- RISCV.cpp ----------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #include "InputFiles.h"
 #include "SyntheticSections.h"
 #include "Target.h"
 
 using namespace llvm;
 using namespace llvm::object;
 using namespace llvm::support::endian;
 using namespace llvm::ELF;
-using namespace lld;
-using namespace lld::elf;
+
+namespace lld {
+namespace elf {
 
 namespace {
 
 class RISCV final : public TargetInfo {
 public:
   RISCV();
   uint32_t calcEFlags() const override;
   void writeGotHeader(uint8_t *buf) const override;
void RISCV::relocateOne(uint8_t *loc, const RelType type,
   case R_RISCV_GPREL_S:
   default:
     error(getErrorLocation(loc) +
           "unimplemented relocation: " + toString(type));
     return;
   }
 }
 
-TargetInfo *elf::getRISCVTargetInfo() {
+TargetInfo *getRISCVTargetInfo() {
   static RISCV target;
   return ⌖
 }
+
+} // namespace elf
+} // namespace lld

ELF/Arch/SPARCV9.cpp

 #include "SyntheticSections.h"
 #include "Target.h"
 #include "lld/Common/ErrorHandler.h"
 #include "llvm/Support/Endian.h"
 
 using namespace llvm;
 using namespace llvm::support::endian;
 using namespace llvm::ELF;
-using namespace lld;
-using namespace lld::elf;
+
+namespace lld {
+namespace elf {
 
 namespace {
 class SPARCV9 final : public TargetInfo {
 public:
   SPARCV9();
   RelExpr getRelExpr(RelType type, const Symbol &s,
                      const uint8_t *loc) const override;
   void writePlt(uint8_t *buf, uint64_t gotEntryAddr, uint64_t pltEntryAddr,
void SPARCV9::writePlt(uint8_t *buf, uint64_t gotEntryAddr,
   };
   memcpy(buf, pltData, sizeof(pltData));
 
   uint64_t off = pltHeaderSize + pltEntrySize * index;
   relocateOne(buf, R_SPARC_22, off);
   relocateOne(buf + 4, R_SPARC_WDISP19, -(off + 4 - pltEntrySize));
 }
 
-TargetInfo *elf::getSPARCV9TargetInfo() {
+TargetInfo *getSPARCV9TargetInfo() {
   static SPARCV9 target;
   return ⌖
 }
+
+} // namespace elf
+} // namespace lld

ELF/Arch/X86.cpp

 #include "SyntheticSections.h"
 #include "Target.h"
 #include "lld/Common/ErrorHandler.h"
 #include "llvm/Support/Endian.h"
 
 using namespace llvm;
 using namespace llvm::support::endian;
 using namespace llvm::ELF;
-using namespace lld;
-using namespace lld::elf;
+
+namespace lld {
+namespace elf {
 
 namespace {
 class X86 : public TargetInfo {
 public:
   X86();
   int getTlsGdRelaxSkip(RelType type) const override;
   RelExpr getRelExpr(RelType type, const Symbol &s,
                      const uint8_t *loc) const override;
void RetpolineNoPic::writePlt(uint8_t *buf, uint64_t gotPltEntryAddr,
   unsigned off = pltHeaderSize + pltEntrySize * index;
   write32le(buf + 2, gotPltEntryAddr);
   write32le(buf + 7, -off - 11 + 32);
   write32le(buf + 12, -off - 16 + 17);
   write32le(buf + 17, relOff);
   write32le(buf + 22, -off - 26);
 }
 
-TargetInfo *elf::getX86TargetInfo() {
+TargetInfo *getX86TargetInfo() {
   if (config->zRetpolineplt) {
     if (config->isPic) {
       static RetpolinePic t;
       return &t;
     }
     static RetpolineNoPic t;
     return &t;
   }
 
   static X86 t;
   return &t;
 }
+
+} // namespace elf
+} // namespace lld

ELF/Arch/X86_64.cpp

 #include "lld/Common/ErrorHandler.h"
 #include "llvm/Object/ELF.h"
 #include "llvm/Support/Endian.h"
 
 using namespace llvm;
 using namespace llvm::object;
 using namespace llvm::support::endian;
 using namespace llvm::ELF;
-using namespace lld;
-using namespace lld::elf;
+
+namespace lld {
+namespace elf {
 
 namespace {
 class X86_64 : public TargetInfo {
 public:
   X86_64();
   int getTlsGdRelaxSkip(RelType type) const override;
   RelExpr getRelExpr(RelType type, const Symbol &s,
                      const uint8_t *loc) const override;
if (config->zRetpolineplt) {
     static Retpoline t;
     return &t;
   }
 
   static X86_64 t;
   return &t;
 }
 
-TargetInfo *elf::getX86_64TargetInfo() { return getTargetInfo(); }
+TargetInfo *getX86_64TargetInfo() { return getTargetInfo(); }
+
+} // namespace elf
+} // namespace lld

ELF/CallGraphSort.cpp

 //===----------------------------------------------------------------------===//
 
 #include "CallGraphSort.h"
 #include "OutputSections.h"
 #include "SymbolTable.h"
 #include "Symbols.h"
 
 using namespace llvm;
-using namespace lld;
-using namespace lld::elf;
+
+namespace lld {
+namespace elf {
 
 namespace {
 struct Edge {
   int from;
   uint64_t weight;
 };
 
 struct Cluster {
DenseMap<const InputSectionBase *, int> CallGraphSort::run() {
   return orderMap;
 }
 
 // Sort sections by the profile data provided by -callgraph-profile-file
 //
 // This first builds a call graph based on the profile data then merges sections
 // according to the C³ huristic. All clusters are then sorted by a density
 // metric to further improve locality.
-DenseMap<const InputSectionBase *, int> elf::computeCallGraphProfileOrder() {
+DenseMap<const InputSectionBase *, int> computeCallGraphProfileOrder() {
   return CallGraphSort().run();
 }
+
+} // namespace elf
+} // namespace lld

ELF/DWARF.cpp

 #include "Symbols.h"
 #include "Target.h"
 #include "lld/Common/Memory.h"
 #include "llvm/DebugInfo/DWARF/DWARFDebugPubTable.h"
 #include "llvm/Object/ELFObjectFile.h"
 
 using namespace llvm;
 using namespace llvm::object;
-using namespace lld;
-using namespace lld::elf;
 
+namespace lld {
+namespace elf {
 template <class ELFT> LLDDwarfObj<ELFT>::LLDDwarfObj(ObjFile<ELFT> *obj) {
   for (InputSectionBase *sec : obj->getSections()) {
     if (!sec)
       continue;
 
     if (LLDDWARFSection *m =
             StringSwitch<LLDDWARFSection *>(sec->name)
                 .Case(".debug_addr", &addrSection)

 Optional<RelocAddrEntry> LLDDwarfObj<ELFT>::find(const llvm::DWARFSection &s,
                                                  uint64_t pos) const {
   auto &sec = static_cast<const LLDDWARFSection &>(s);
   if (sec.sec->areRelocsRela)
     return findAux(*sec.sec, pos, sec.sec->template relas<ELFT>());
   return findAux(*sec.sec, pos, sec.sec->template rels<ELFT>());
 }
 
-template class elf::LLDDwarfObj<ELF32LE>;
-template class elf::LLDDwarfObj<ELF32BE>;
-template class elf::LLDDwarfObj<ELF64LE>;
-template class elf::LLDDwarfObj<ELF64BE>;
+template class LLDDwarfObj<ELF32LE>;
+template class LLDDwarfObj<ELF32BE>;
+template class LLDDwarfObj<ELF64LE>;
+template class LLDDwarfObj<ELF64BE>;
+
+} // namespace elf
+} // namespace lld

ELF/Driver.cpp

 #include <utility>
 
 using namespace llvm;
 using namespace llvm::ELF;
 using namespace llvm::object;
 using namespace llvm::sys;
 using namespace llvm::support;
 
-using namespace lld;
-using namespace lld::elf;
+namespace lld {
+namespace elf {
 
-Configuration *elf::config;
-LinkerDriver *elf::driver;
+Configuration *config;
+LinkerDriver *driver;
 
 static void setConfigs(opt::InputArgList &args);
 static void readConfigs(opt::InputArgList &args);
 
-bool elf::link(ArrayRef<const char *> args, bool canExitEarly,
-               raw_ostream &error) {
+bool link(ArrayRef<const char *> args, bool canExitEarly, raw_ostream &error) {
   errorHandler().logName = args::getFilenameWithoutExe(args[0]);
   errorHandler().errorLimitExceededMsg =
       "too many errors emitted, stopping now (use "
       "-error-limit=0 to see all errors)";
   errorHandler().errorOS = &error;
   errorHandler().exitEarly = canExitEarly;
   enableColors(error.has_colors());
 
if (auto *arg = args.getLastArg(OPT_call_graph_ordering_file))
       if (Optional<MemoryBufferRef> buffer = readFile(arg->getValue()))
         readCallGraph(*buffer);
     readCallGraphsFromObjectFiles<ELFT>();
   }
 
   // Write the result to the file.
   writeResult<ELFT>();
 }
+
+} // namespace elf
+} // namespace lld

ELF/DriverUtils.cpp

 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/Process.h"
 
 using namespace llvm;
 using namespace llvm::sys;
 using namespace llvm::opt;
 
-using namespace lld;
-using namespace lld::elf;
+namespace lld {
+namespace elf {
 
 // Create OptTable
 
 // Create prefix string literals used in Options.td
 #define PREFIX(NAME, VALUE) const char *const NAME[] = VALUE;
 #include "Options.inc"
 #undef PREFIX
 
if (findNearest(arg->getAsString(args), nearest) > 1)
       error("unknown argument '" + arg->getAsString(args) + "'");
     else
       error("unknown argument '" + arg->getAsString(args) +
             "', did you mean '" + nearest + "'");
   }
   return args;
 }
 
-void elf::printHelp() {
+void printHelp() {
   ELFOptTable().PrintHelp(
       outs(), (config->progName + " [options] file...").str().c_str(), "lld",
       false /*ShowHidden*/, true /*ShowAllAliases*/);
   outs() << "\n";
 
   // Scripts generated by Libtool versions up to at least 2.4.6 (the most
   // recent version as of March 2017) expect /: supported targets:.* elf/
   // in a message for the -help option. If it doesn't match, the scripts
   // assume that the linker doesn't support very basic features such as
   // shared libraries. Therefore, we need to print out at least "elf".
   outs() << config->progName << ": supported targets: elf\n";
 }
 
 static std::string rewritePath(StringRef s) {
   if (fs::exists(s))
     return relativeToRoot(s);
   return s;
 }
 
 // Reconstructs command line arguments so that so that you can re-run
 // the same command with the same inputs. This is for --reproduce.
-std::string elf::createResponseFile(const opt::InputArgList &args) {
+std::string createResponseFile(const opt::InputArgList &args) {
   SmallString<0> data;
   raw_svector_ostream os(data);
   os << "--chroot .\n";
 
   // Copy the command line to the output while rewriting paths.
   for (auto *arg : args) {
     switch (arg->getOption().getID()) {
     case OPT_reproduce:
static Optional<std::string> findFile(StringRef path1, const Twine &path2) {
   else
     path::append(s, path1, path2);
 
   if (fs::exists(s))
     return s.str().str();
   return None;
 }
 
-Optional<std::string> elf::findFromSearchPaths(StringRef path) {
+Optional<std::string> findFromSearchPaths(StringRef path) {
   for (StringRef dir : config->searchPaths)
     if (Optional<std::string> s = findFile(dir, path))
       return s;
   return None;
 }
 
 // This is for -l<basename>. We'll look for lib<basename>.so or lib<basename>.a from
 // search paths.
-Optional<std::string> elf::searchLibraryBaseName(StringRef name) {
+Optional<std::string> searchLibraryBaseName(StringRef name) {
   for (StringRef dir : config->searchPaths) {
     if (!config->isStatic)
       if (Optional<std::string> s = findFile(dir, "lib" + name + ".so"))
         return s;
     if (Optional<std::string> s = findFile(dir, "lib" + name + ".a"))
       return s;
   }
   return None;
 }
 
 // This is for -l<namespec>.
-Optional<std::string> elf::searchLibrary(StringRef name) {
-    if (name.startswith(":"))
-        return findFromSearchPaths(name.substr(1));
-    return searchLibraryBaseName (name);
+Optional<std::string> searchLibrary(StringRef name) {
+  return searchLibraryBaseName(name);
 }
 
 // If a linker/version script doesn't exist in the current directory, we also
 // look for the script in the '-L' search paths. This matches the behaviour of
 // '-T', --version-script=, and linker script INPUT() command in ld.bfd.
-Optional<std::string> elf::searchScript(StringRef name) {
+Optional<std::string> searchScript(StringRef name) {
   if (fs::exists(name))
     return name.str();
   return findFromSearchPaths(name);
 }
+
+} // namespace elf
+} // namespace lld

ELF/EhFrame.cpp

 #include "llvm/BinaryFormat/Dwarf.h"
 #include "llvm/Object/ELF.h"
 
 using namespace llvm;
 using namespace llvm::ELF;
 using namespace llvm::dwarf;
 using namespace llvm::object;
 
-using namespace lld;
-using namespace lld::elf;
-
+namespace lld {
+namespace elf {
 namespace {
 class EhReader {
 public:
   EhReader(InputSectionBase *s, ArrayRef<uint8_t> d) : isec(s), d(d) {}
   size_t readEhRecordSize();
   uint8_t getFdeEncoding();
 
 private:
   template <class P> void failOn(const P *loc, const Twine &msg) {
     fatal("corrupted .eh_frame: " + msg + "\n>>> defined in " +
           isec->getObjMsg((const uint8_t *)loc - isec->data().data()));
   }
 
   uint8_t readByte();
   void skipBytes(size_t count);
   StringRef readString();
   void skipLeb128();
   void skipAugP();
 
   InputSectionBase *isec;
   ArrayRef<uint8_t> d;
 };
 }
 
-size_t elf::readEhRecordSize(InputSectionBase *s, size_t off) {
+size_t readEhRecordSize(InputSectionBase *s, size_t off) {
   return EhReader(s, s->data().slice(off)).readEhRecordSize();
 }
 
 // .eh_frame section is a sequence of records. Each record starts with
 // a 4 byte length field. This function reads the length.
 size_t EhReader::readEhRecordSize() {
   if (d.size() < 4)
     failOn(d.data(), "CIE/FDE too small");
void EhReader::skipAugP() {
   size_t size = getAugPSize(enc);
   if (size == 0)
     failOn(d.data() - 1, "unknown FDE encoding");
   if (size >= d.size())
     failOn(d.data() - 1, "corrupted CIE");
   d = d.slice(size);
 }
 
-uint8_t elf::getFdeEncoding(EhSectionPiece *p) {
+uint8_t getFdeEncoding(EhSectionPiece *p) {
   return EhReader(p->sec, p->data()).getFdeEncoding();
 }
 
 uint8_t EhReader::getFdeEncoding() {
   skipBytes(8);
   int version = readByte();
   if (version != 1 && version != 3)
     failOn(d.data() - 1,
for (char c : aug) {
     if (c == 'L') {
       readByte();
       continue;
     }
     failOn(aug.data(), "unknown .eh_frame augmentation string: " + aug);
   }
   return DW_EH_PE_absptr;
 }
+
+} // namespace elf
+} // namespace lld

ELF/ICF.cpp

 #include "lld/Common/Threads.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/BinaryFormat/ELF.h"
 #include "llvm/Object/ELF.h"
 #include "llvm/Support/xxhash.h"
 #include <algorithm>
 #include <atomic>
 
-using namespace lld;
-using namespace lld::elf;
 using namespace llvm;
 using namespace llvm::ELF;
 using namespace llvm::object;
 
+namespace lld {
+namespace elf {
 namespace {
 template <class ELFT> class ICF {
 public:
   void run();
 
 private:
   void segregate(size_t begin, size_t end, bool constant);
 
for (BaseCommand *base : script->sectionCommands)
     if (auto *sec = dyn_cast<OutputSection>(base))
       for (BaseCommand *sub_base : sec->sectionCommands)
         if (auto *isd = dyn_cast<InputSectionDescription>(sub_base))
           llvm::erase_if(isd->sections,
                          [](InputSection *isec) { return !isec->isLive(); });
 }
 
 // ICF entry point function.
-template <class ELFT> void elf::doIcf() { ICF<ELFT>().run(); }
+template <class ELFT> void doIcf() { ICF<ELFT>().run(); }
 
-template void elf::doIcf<ELF32LE>();
-template void elf::doIcf<ELF32BE>();
-template void elf::doIcf<ELF64LE>();
-template void elf::doIcf<ELF64BE>();
+template void doIcf<ELF32LE>();
+template void doIcf<ELF32BE>();
+template void doIcf<ELF64LE>();
+template void doIcf<ELF64BE>();
+
+} // namespace elf
+} // namespace lld

ELF/InputFiles.h

 class TarWriter;
 struct DILineInfo;
 namespace lto {
 class InputFile;
 }
 } // namespace llvm
 
 namespace lld {
-namespace elf {
-class InputFile;
-class InputSectionBase;
-}
 
 // Returns "<internal>", "foo.a(bar.o)" or "baz.o".
 std::string toString(const elf::InputFile *f);
 
 namespace elf {
+class InputFile;
+class InputSectionBase;
 
 using llvm::object::Archive;
 
 class Symbol;
 
 // If -reproduce option is given, all input files are written
 // to this tar archive.
 extern std::unique_ptr<llvm::TarWriter> tar;

ELF/InputFiles.cpp

 
 using namespace llvm;
 using namespace llvm::ELF;
 using namespace llvm::object;
 using namespace llvm::sys;
 using namespace llvm::sys::fs;
 using namespace llvm::support::endian;
 
-using namespace lld;
-using namespace lld::elf;
+namespace lld {
+// Returns "<internal>", "foo.a(bar.o)" or "baz.o".
+std::string toString(const elf::InputFile *f) {
+  if (!f)
+    return "<internal>";
 
+  if (f->toStringCache.empty()) {
+    if (f->archiveName.empty())
+      f->toStringCache = f->getName();
+    else
+      f->toStringCache = (f->archiveName + "(" + f->getName() + ")").str();
+  }
+  return f->toStringCache;
+}
+
+namespace elf {
 bool InputFile::isInGroup;
 uint32_t InputFile::nextGroupId;
-std::vector<BinaryFile *> elf::binaryFiles;
-std::vector<BitcodeFile *> elf::bitcodeFiles;
-std::vector<LazyObjFile *> elf::lazyObjFiles;
-std::vector<InputFile *> elf::objectFiles;
-std::vector<SharedFile *> elf::sharedFiles;
+std::vector<BinaryFile *> binaryFiles;
+std::vector<BitcodeFile *> bitcodeFiles;
+std::vector<LazyObjFile *> lazyObjFiles;
+std::vector<InputFile *> objectFiles;
+std::vector<SharedFile *> sharedFiles;
 
-std::unique_ptr<TarWriter> elf::tar;
+std::unique_ptr<TarWriter> tar;
 
 static ELFKind getELFKind(MemoryBufferRef mb, StringRef archiveName) {
   unsigned char size;
   unsigned char endian;
   std::tie(size, endian) = getElfArchType(mb.getBuffer());
 
   auto report = [&](StringRef msg) {
     StringRef filename = mb.getBufferIdentifier();

 InputFile::InputFile(Kind k, MemoryBufferRef m)
     : mb(m), groupId(nextGroupId), fileKind(k) {
   // All files within the same --{start,end}-group get the same group ID.
   // Otherwise, a new file will get a new group ID.
   if (!isInGroup)
     ++nextGroupId;
 }
 
-Optional<MemoryBufferRef> elf::readFile(StringRef path) {
+Optional<MemoryBufferRef> readFile(StringRef path) {
   // The --chroot option changes our virtual root directory.
   // This is useful when you are dealing with files created by --reproduce.
   if (!config->chroot.empty() && path.startswith("/"))
     path = saver.save(config->chroot + path);
 
   log(path);
 
   auto mbOrErr = MemoryBuffer::getFile(path, -1, false);
template <class ELFT> static void doParseFile(InputFile *file) {
   }
 
   // Regular object file
   objectFiles.push_back(file);
   cast<ObjFile<ELFT>>(file)->parse();
 }
 
 // Add symbols in File to the symbol table.
-void elf::parseFile(InputFile *file) {
+void parseFile(InputFile *file) {
   switch (config->ekind) {
   case ELF32LEKind:
     doParseFile<ELF32LE>(file);
     return;
   case ELF32BEKind:
     doParseFile<ELF32BE>(file);
     return;
   case ELF64LEKind:
for (const llvm::DWARFDebugLine::LineTable *lt : lineTables) {
     if (lt->getFileLineInfoForAddress(
             {s->getOffsetInFile() + offset, sectionIndex}, nullptr,
             DILineInfoSpecifier::FileLineInfoKind::AbsoluteFilePath, info))
       return info;
   }
   return None;
 }
 
-// Returns "<internal>", "foo.a(bar.o)" or "baz.o".
-std::string lld::toString(const InputFile *f) {
-  if (!f)
-    return "<internal>";
-
-  if (f->toStringCache.empty()) {
-    if (f->archiveName.empty())
-      f->toStringCache = f->getName();
-    else
-      f->toStringCache = (f->archiveName + "(" + f->getName() + ")").str();
-  }
-  return f->toStringCache;
-}
-
 ELFFileBase::ELFFileBase(Kind k, MemoryBufferRef mb) : InputFile(k, mb) {
   ekind = getELFKind(mb, "");
 
   switch (ekind) {
   case ELF32LEKind:
     init<ELF32LE>();
     break;
   case ELF32BEKind:
void BinaryFile::parse() {
   symtab->addSymbol(Defined{nullptr, saver.save(s + "_start"), STB_GLOBAL,
                             STV_DEFAULT, STT_OBJECT, 0, 0, section});
   symtab->addSymbol(Defined{nullptr, saver.save(s + "_end"), STB_GLOBAL,
                             STV_DEFAULT, STT_OBJECT, data.size(), 0, section});
   symtab->addSymbol(Defined{nullptr, saver.save(s + "_size"), STB_GLOBAL,
                             STV_DEFAULT, STT_OBJECT, data.size(), 0, nullptr});
 }
 
-InputFile *elf::createObjectFile(MemoryBufferRef mb, StringRef archiveName,
-                                 uint64_t offsetInArchive) {
+InputFile *createObjectFile(MemoryBufferRef mb, StringRef archiveName,
   if (isBitcode(mb))
     return make<BitcodeFile>(mb, archiveName, offsetInArchive);
 
   switch (getELFKind(mb, archiveName)) {
   case ELF32LEKind:
     return make<ObjFile<ELF32LE>>(mb, archiveName);
   case ELF32BEKind:
     return make<ObjFile<ELF32BE>>(mb, archiveName);
for (Symbol *sym : this->symbols) {
       // MemoryBuffer is emptied if this file is instantiated as ObjFile.
       if (mb.getBuffer().empty())
         return;
     }
     return;
   }
 }
 
-std::string elf::replaceThinLTOSuffix(StringRef path) {
+std::string replaceThinLTOSuffix(StringRef path) {
   StringRef suffix = config->thinLTOObjectSuffixReplace.first;
   StringRef repl = config->thinLTOObjectSuffixReplace.second;
 
   if (path.consume_back(suffix))
     return (path + repl).str();
   return path;
 }
 
 template void BitcodeFile::parse<ELF32LE>();
 template void BitcodeFile::parse<ELF32BE>();
 template void BitcodeFile::parse<ELF64LE>();
 template void BitcodeFile::parse<ELF64BE>();
 
 template void LazyObjFile::parse<ELF32LE>();
 template void LazyObjFile::parse<ELF32BE>();
 template void LazyObjFile::parse<ELF64LE>();
 template void LazyObjFile::parse<ELF64BE>();
 
-template class elf::ObjFile<ELF32LE>;
-template class elf::ObjFile<ELF32BE>;
-template class elf::ObjFile<ELF64LE>;
-template class elf::ObjFile<ELF64BE>;
+template class ObjFile<ELF32LE>;
+template class ObjFile<ELF32BE>;
+template class ObjFile<ELF64LE>;
+template class ObjFile<ELF64BE>;
 
 template void SharedFile::parse<ELF32LE>();
 template void SharedFile::parse<ELF32BE>();
 template void SharedFile::parse<ELF64LE>();
 template void SharedFile::parse<ELF64BE>();
+
+} // namespace elf
+} // namespace lld

ELF/InputSection.cpp

 
 using namespace llvm;
 using namespace llvm::ELF;
 using namespace llvm::object;
 using namespace llvm::support;
 using namespace llvm::support::endian;
 using namespace llvm::sys;
 
-using namespace lld;
-using namespace lld::elf;
-
-std::vector<InputSectionBase *> elf::inputSections;
-
+namespace lld {
 // Returns a string to construct an error message.
-std::string lld::toString(const InputSectionBase *sec) {
+std::string toString(const elf::InputSectionBase *sec) {
   return (toString(sec->file) + ":(" + sec->name + ")").str();
 }
 
+namespace elf {
+std::vector<InputSectionBase *> inputSections;
+
 template <class ELFT>
 static ArrayRef<uint8_t> getSectionContents(ObjFile<ELFT> &file,
                                             const typename ELFT::Shdr &hdr) {
   if (hdr.sh_type == SHT_NOBITS)
     return makeArrayRef<uint8_t>(nullptr, hdr.sh_size);
   return check(file.getObj().getSectionContents(&hdr));
 }
 
static int64_t getTlsTpOffset(const Symbol &s) {
   // Variant 1. TP will be followed by an optional gap (which is the size of 2
   // pointers on ARM/AArch64, 0 on other targets), followed by alignment
   // padding, then the static TLS blocks. The alignment padding is added so that
   // (TP + gap + padding) is congruent to p_vaddr modulo p_align.
   //
   // Variant 2. Static TLS blocks, followed by alignment padding are placed
   // before TP. The alignment padding is added so that (TP - padding -
   // p_memsz) is congruent to p_vaddr modulo p_align.
-  elf::PhdrEntry *tls = Out::tlsPhdr;
+  PhdrEntry *tls = Out::tlsPhdr;
   switch (config->emachine) {
     // Variant 1.
   case EM_ARM:
   case EM_AARCH64:
     return s.getVA(0) + config->wordsize * 2 +
            ((tls->p_vaddr - config->wordsize * 2) & (tls->p_align - 1));
   case EM_MIPS:
   case EM_PPC:
if (enclosingPrologueAttempted(rel.offset, prologues))
       continue;
 
     if (Defined *f = getEnclosingFunction<ELFT>(rel.offset)) {
       prologues.insert(f);
       if (target->adjustPrologueForCrossSplitStack(buf + getOffset(f->value),
                                                    end, f->stOther))
         continue;
       if (!getFile<ELFT>()->someNoSplitStack)
-        error(lld::toString(this) + ": " + f->getName() +
+        error(toString(this) + ": " + f->getName() +
               " (with -fsplit-stack) calls " + rel.sym->getName() +
               " (without -fsplit-stack), but couldn't adjust its prologue");
     }
   }
 
   if (target->needsMoreStackNonSplit)
     switchMorestackCallsToMorestackNonSplit(prologues, morestackCalls);
 }
template EhInputSection::EhInputSection(ObjFile<ELF64LE> &,
                                         const ELF64LE::Shdr &, StringRef);
 template EhInputSection::EhInputSection(ObjFile<ELF64BE> &,
                                         const ELF64BE::Shdr &, StringRef);
 
 template void EhInputSection::split<ELF32LE>();
 template void EhInputSection::split<ELF32BE>();
 template void EhInputSection::split<ELF64LE>();
 template void EhInputSection::split<ELF64BE>();
+
+} // namespace elf
+} // namespace lld

ELF/LTO.cpp

 #include <string>
 #include <system_error>
 #include <vector>
 
 using namespace llvm;
 using namespace llvm::object;
 using namespace llvm::ELF;
 
-using namespace lld;
-using namespace lld::elf;
+namespace lld {
+namespace elf {
 
 // Creates an empty file to store a list of object files for final
 // linking of distributed ThinLTO.
 static std::unique_ptr<raw_fd_ostream> openFile(StringRef file) {
   std::error_code ec;
   auto ret =
       std::make_unique<raw_fd_ostream>(file, ec, sys::fs::OpenFlags::OF_None);
   if (ec) {
for (unsigned i = 0; i != maxTasks; ++i)
     if (!buf[i].empty())
       ret.push_back(createObjectFile(MemoryBufferRef(buf[i], "lto.tmp")));
 
   for (std::unique_ptr<MemoryBuffer> &file : files)
     if (file)
       ret.push_back(createObjectFile(*file));
   return ret;
 }
+
+} // namespace elf
+} // namespace lld

ELF/LinkerScript.cpp

 #include <limits>
 #include <string>
 #include <vector>
 
 using namespace llvm;
 using namespace llvm::ELF;
 using namespace llvm::object;
 using namespace llvm::support::endian;
-using namespace lld;
-using namespace lld::elf;
 
-LinkerScript *elf::script;
+namespace lld {
+namespace elf {
+LinkerScript *script;
 
 static uint64_t getOutputSectionVA(SectionBase *sec) {
   OutputSection *os = sec->getOutputSection();
   assert(os && "input section has no output section assigned");
   return os ? os->addr : 0;
 }
 
 uint64_t ExprValue::getValue() const {
for (StringRef s : cmd->phdrs) {
     if (Optional<size_t> idx = getPhdrIndex(phdrsCommands, s))
       ret.push_back(*idx);
     else if (s != "NONE")
       error(cmd->location + ": section header '" + s +
             "' is not listed in PHDRS");
   }
   return ret;
 }
+
+} // namespace elf
+} // namespace lld

ELF/MapFile.cpp

 #include "lld/Common/Threads.h"
 #include "llvm/ADT/MapVector.h"
 #include "llvm/ADT/SetVector.h"
 #include "llvm/Support/raw_ostream.h"
 
 using namespace llvm;
 using namespace llvm::object;
 
-using namespace lld;
-using namespace lld::elf;
-
+namespace lld {
+namespace elf {
 using SymbolMapTy = DenseMap<const SectionBase *, SmallVector<Defined *, 4>>;
 
 static constexpr char indent8[] = "        ";          // 8 spaces
 static constexpr char indent16[] = "                "; // 16 spaces
 
 // Print out the first three columns of a line.
 static void writeHeader(raw_ostream &os, uint64_t vma, uint64_t lma,
                         uint64_t size, uint64_t align) {
static void printEhFrame(raw_ostream &os, const EhFrameSection *sec) {
   for (EhSectionPiece &p : pieces) {
     writeHeader(os, osec->addr + p.outputOff, osec->getLMA() + p.outputOff,
                 p.size, 1);
     os << indent8 << toString(p.sec->file) << ":(" << p.sec->name << "+0x"
        << Twine::utohexstr(p.inputOff) + ")\n";
   }
 }
 
-void elf::writeMapFile() {
+void writeMapFile() {
   if (config->mapFile.empty())
     return;
 
   // Open a map file for writing.
   std::error_code ec;
   raw_fd_ostream os(config->mapFile, ec, sys::fs::OF_None);
   if (ec) {
     error("cannot open " + config->mapFile + ": " + ec.message());

 // followed by files that uses that symbol. Here is an example.
 //
 //     strlen     /lib/x86_64-linux-gnu/libc.so.6
 //                tools/lld/tools/lld/CMakeFiles/lld.dir/lld.cpp.o
 //                lib/libLLVMSupport.a(PrettyStackTrace.cpp.o)
 //
 // In this case, strlen is defined by libc.so.6 and used by other two
 // files.
-void elf::writeCrossReferenceTable() {
+void writeCrossReferenceTable() {
   if (!config->cref)
     return;
 
   // Collect symbols and files.
   MapVector<Symbol *, SetVector<InputFile *>> map;
   for (InputFile *file : objectFiles) {
     for (Symbol *sym : file->getSymbols()) {
       if (isa<SharedSymbol>(sym))
for (auto kv : map) {
     SetVector<InputFile *> &files = kv.second;
 
     print(toString(*sym), toString(sym->file));
     for (InputFile *file : files)
       if (file != sym->file)
         print("", toString(file));
   }
 }
+
+} // namespace elf
+} // namespace lld

ELF/MarkLive.cpp

 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Object/ELF.h"
 #include <functional>
 #include <vector>
 
 using namespace llvm;
 using namespace llvm::ELF;
 using namespace llvm::object;
-using namespace llvm::support::endian;
 
-using namespace lld;
-using namespace lld::elf;
+namespace endian = llvm::support::endian;
 
+namespace lld {
+namespace elf {
 namespace {
 template <class ELFT> class MarkLive {
 public:
   MarkLive(unsigned partition) : partition(partition) {}
 
   void run();
   void moveToMain();
 

 void MarkLive<ELFT>::scanEhFrameSection(EhInputSection &eh,
                                         ArrayRef<RelTy> rels) {
   for (size_t i = 0, end = eh.pieces.size(); i < end; ++i) {
     EhSectionPiece &piece = eh.pieces[i];
     size_t firstRelI = piece.firstRelocation;
     if (firstRelI == (unsigned)-1)
       continue;
 
-    if (read32<ELFT::TargetEndianness>(piece.data().data() + 4) == 0) {
+    if (endian::read32<ELFT::TargetEndianness>(piece.data().data() + 4) == 0) {
       // This is a CIE, we only need to worry about the first relocation. It is
       // known to point to the personality function.
       resolveReloc(eh, rels[firstRelI], false);
       continue;
     }
 
     // This is a FDE. The relocations point to the described function or to
     // a LSDA. We only need to keep the LSDA alive, so ignore anything that
template <class ELFT> void MarkLive<ELFT>::moveToMain() {
   }
 
   mark();
 }
 
 // Before calling this function, Live bits are off for all
 // input sections. This function make some or all of them on
 // so that they are emitted to the output file.
-template <class ELFT> void elf::markLive() {
+template <class ELFT> void markLive() {
   // If -gc-sections is not given, no sections are removed.
   if (!config->gcSections) {
     for (InputSectionBase *sec : inputSections)
       sec->markLive();
 
     // If a DSO defines a symbol referenced in a regular object, it is needed.
     symtab->forEachSymbol([](Symbol *sym) {
       if (auto *s = dyn_cast<SharedSymbol>(sym))
template <class ELFT> void markLive() {
 
   // Report garbage-collected sections.
   if (config->printGcSections)
     for (InputSectionBase *sec : inputSections)
       if (!sec->isLive())
         message("removing unused section " + toString(sec));
 }
 
-template void elf::markLive<ELF32LE>();
-template void elf::markLive<ELF32BE>();
-template void elf::markLive<ELF64LE>();
-template void elf::markLive<ELF64BE>();
+template void markLive<ELF32LE>();
+template void markLive<ELF32BE>();
+template void markLive<ELF64LE>();
+template void markLive<ELF64BE>();
+
+} // namespace elf
+} // namespace lld

ELF/OutputSections.cpp

 #include "llvm/Support/SHA1.h"
 
 using namespace llvm;
 using namespace llvm::dwarf;
 using namespace llvm::object;
 using namespace llvm::support::endian;
 using namespace llvm::ELF;
 
-using namespace lld;
-using namespace lld::elf;
-
+namespace lld {
+namespace elf {
 uint8_t *Out::bufferStart;
 uint8_t Out::first;
 PhdrEntry *Out::tlsPhdr;
 OutputSection *Out::elfHeader;
 OutputSection *Out::programHeaders;
 OutputSection *Out::preinitArray;
 OutputSection *Out::initArray;
 OutputSection *Out::finiArray;
 
-std::vector<OutputSection *> elf::outputSections;
+std::vector<OutputSection *> outputSections;
 
 uint32_t OutputSection::getPhdrFlags() const {
   uint32_t ret = 0;
   if (config->emachine != EM_ARM || !(flags & SHF_ARM_PURECODE))
     ret |= PF_R;
   if (flags & SHF_WRITE)
     ret |= PF_W;
   if (flags & SHF_EXECINSTR)
static void sortByOrder(MutableArrayRef<InputSection *> in,
   for (InputSection *s : in)
     v.push_back({order(s), s});
   llvm::stable_sort(v, less_first());
 
   for (size_t i = 0; i < v.size(); ++i)
     in[i] = v[i].second;
 }
 
-uint64_t elf::getHeaderSize() {
+uint64_t getHeaderSize() {
   if (config->oFormatBinary)
     return 0;
   return Out::elfHeader->size + Out::programHeaders->size;
 }
 
 bool OutputSection::classof(const BaseCommand *c) {
   return c->kind == OutputSectionKind;
 }
void OutputSection::sortCtorsDtors() {
   assert(sectionCommands.size() == 1);
   auto *isd = cast<InputSectionDescription>(sectionCommands[0]);
   llvm::stable_sort(isd->sections, compCtors);
 }
 
 // If an input string is in the form of "foo.N" where N is a number,
 // return N. Otherwise, returns 65536, which is one greater than the
 // lowest priority.
-int elf::getPriority(StringRef s) {
+int getPriority(StringRef s) {
   size_t pos = s.rfind('.');
   if (pos == StringRef::npos)
     return 65536;
   int v;
   if (!to_integer(s.substr(pos + 1), v, 10))
     return 65536;
   return v;
 }
 
-std::vector<InputSection *> elf::getInputSections(OutputSection *os) {
+std::vector<InputSection *> getInputSections(OutputSection *os) {
   std::vector<InputSection *> ret;
   for (BaseCommand *base : os->sectionCommands)
     if (auto *isd = dyn_cast<InputSectionDescription>(base))
       ret.insert(ret.end(), isd->sections.begin(), isd->sections.end());
   return ret;
 }
 
 // Sorts input sections by section name suffixes, so that .foo.N comes

 template void OutputSection::writeTo<ELF32BE>(uint8_t *Buf);
 template void OutputSection::writeTo<ELF64LE>(uint8_t *Buf);
 template void OutputSection::writeTo<ELF64BE>(uint8_t *Buf);
 
 template void OutputSection::maybeCompress<ELF32LE>();
 template void OutputSection::maybeCompress<ELF32BE>();
 template void OutputSection::maybeCompress<ELF64LE>();
 template void OutputSection::maybeCompress<ELF64BE>();
+
+} // namespace elf
+} // namespace lld

ELF/Relocations.cpp

 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
 
 using namespace llvm;
 using namespace llvm::ELF;
 using namespace llvm::object;
 using namespace llvm::support::endian;
 
-using namespace lld;
-using namespace lld::elf;
-
+namespace lld {
+namespace elf {
 static Optional<std::string> getLinkerScriptLocation(const Symbol &sym) {
   for (BaseCommand *base : script->sectionCommands)
     if (auto *cmd = dyn_cast<SymbolAssignment>(base))
       if (cmd->sym == &sym)
         return cmd->location;
   return None;
 }
 
msg += "\nthe vtable symbol may be undefined because the class is missing "
            "its key function (see https://lld.llvm.org/missingkeyfunction)";
 
   if (undef.isWarning)
     warn(msg);
   else
     error(msg);
 }
 
-template <class ELFT> void elf::reportUndefinedSymbols() {
+template <class ELFT> void reportUndefinedSymbols() {
   // Find the first "undefined symbol" diagnostic for each diagnostic, and
   // collect all "referenced from" lines at the first diagnostic.
   DenseMap<Symbol *, UndefinedDiag *> firstRef;
   for (UndefinedDiag &undef : undefs) {
     assert(undef.locs.size() == 1);
     if (UndefinedDiag *canon = firstRef.lookup(undef.sym)) {
       canon->locs.push_back(undef.locs[0]);
       undef.locs.clear();
static void scanRelocs(InputSectionBase &sec, ArrayRef<RelTy> rels) {
   if (config->emachine == EM_RISCV ||
       (config->emachine == EM_PPC64 && sec.name == ".toc"))
     llvm::stable_sort(sec.relocations,
                       [](const Relocation &lhs, const Relocation &rhs) {
                         return lhs.offset < rhs.offset;
                       });
 }
 
-template <class ELFT> void elf::scanRelocations(InputSectionBase &s) {
+template <class ELFT> void scanRelocations(InputSectionBase &s) {
   if (s.areRelocsRela)
     scanRelocs<ELFT>(s, s.relas<ELFT>());
   else
     scanRelocs<ELFT>(s, s.rels<ELFT>());
 }
 
 static bool mergeCmp(const InputSection *a, const InputSection *b) {
   // std::merge requires a strict weak ordering.
for (auto &p : thunkedSections)
     addressesChanged |= p.second->assignOffsets();
 
   // Merge all created synthetic ThunkSections back into OutputSection
   mergeThunks(outputSections);
   ++pass;
   return addressesChanged;
 }
 
-template void elf::scanRelocations<ELF32LE>(InputSectionBase &);
-template void elf::scanRelocations<ELF32BE>(InputSectionBase &);
-template void elf::scanRelocations<ELF64LE>(InputSectionBase &);
-template void elf::scanRelocations<ELF64BE>(InputSectionBase &);
-template void elf::reportUndefinedSymbols<ELF32LE>();
-template void elf::reportUndefinedSymbols<ELF32BE>();
-template void elf::reportUndefinedSymbols<ELF64LE>();
-template void elf::reportUndefinedSymbols<ELF64BE>();
+template void scanRelocations<ELF32LE>(InputSectionBase &);
+template void scanRelocations<ELF32BE>(InputSectionBase &);
+template void scanRelocations<ELF64LE>(InputSectionBase &);
+template void scanRelocations<ELF64BE>(InputSectionBase &);
+template void reportUndefinedSymbols<ELF32LE>();
+template void reportUndefinedSymbols<ELF32BE>();
+template void reportUndefinedSymbols<ELF64LE>();
+template void reportUndefinedSymbols<ELF64BE>();
+
+} // namespace elf
+} // namespace lld

ELF/ScriptLexer.cpp

 //
 //===----------------------------------------------------------------------===//
 
 #include "ScriptLexer.h"
 #include "lld/Common/ErrorHandler.h"
 #include "llvm/ADT/Twine.h"
 
 using namespace llvm;
-using namespace lld;
-using namespace lld::elf;
 
+namespace lld {
+namespace elf {
 // Returns a whole line containing the current token.
 StringRef ScriptLexer::getLine() {
   StringRef s = getCurrentMB().getBuffer();
   StringRef tok = tokens[pos - 1];
 
   size_t pos = s.rfind('\n', tok.data() - s.data());
   if (pos != StringRef::npos)
     s = s.substr(pos + 1);

 MemoryBufferRef ScriptLexer::getCurrentMB() {
   // Find input buffer containing the current token.
   assert(!mbs.empty() && pos > 0);
   for (MemoryBufferRef mb : mbs)
     if (encloses(mb.getBuffer(), tokens[pos - 1]))
       return mb;
   llvm_unreachable("getCurrentMB: failed to find a token");
 }
+
+} // namespace elf
+} // namespace lld

ELF/ScriptParser.cpp

 #include "llvm/Support/Path.h"
 #include <cassert>
 #include <limits>
 #include <vector>
 
 using namespace llvm;
 using namespace llvm::ELF;
 using namespace llvm::support::endian;
-using namespace lld;
-using namespace lld::elf;
 
+namespace lld {
+namespace elf {
 namespace {
 class ScriptParser final : ScriptLexer {
 public:
   ScriptParser(MemoryBufferRef mb) : ScriptLexer(mb) {
     // Initialize IsUnderSysroot
     if (config->sysroot == "")
       return;
     StringRef path = mb.getBufferIdentifier();
if (tok == "SIZEOF") {
     StringRef name = readParenLiteral();
     OutputSection *cmd = script->getOrCreateOutputSection(name);
     // Linker script does not create an output section if its content is empty.
     // We want to allow SIZEOF(.foo) where .foo is a section which happened to
     // be empty.
     return [=] { return cmd->size; };
   }
   if (tok == "SIZEOF_HEADERS")
-    return [=] { return elf::getHeaderSize(); };
+    return [=] { return getHeaderSize(); };
 
   // Tok is the dot.
   if (tok == ".")
     return [=] { return script->getSymbolValue(tok, location); };
 
   // Tok is a literal number.
   if (Optional<uint64_t> val = parseInt(tok))
     return [=] { return *val; };
for (char c : next().lower()) {
     if (invert)
       negFlags |= flag;
     else
       flags |= flag;
   }
   return {flags, negFlags};
 }
 
-void elf::readLinkerScript(MemoryBufferRef mb) {
+void readLinkerScript(MemoryBufferRef mb) {
   ScriptParser(mb).readLinkerScript();
 }
 
-void elf::readVersionScript(MemoryBufferRef mb) {
+void readVersionScript(MemoryBufferRef mb) {
   ScriptParser(mb).readVersionScript();
 }
 
-void elf::readDynamicList(MemoryBufferRef mb) {
-  ScriptParser(mb).readDynamicList();
-}
+void readDynamicList(MemoryBufferRef mb) { ScriptParser(mb).readDynamicList(); }
 
-void elf::readDefsym(StringRef name, MemoryBufferRef mb) {
+void readDefsym(StringRef name, MemoryBufferRef mb) {
   ScriptParser(mb).readDefsym(name);
 }
+
+} // namespace elf
+} // namespace lld

ELF/SymbolTable.cpp

 #include "lld/Common/Memory.h"
 #include "lld/Common/Strings.h"
 #include "llvm/ADT/STLExtras.h"
 
 using namespace llvm;
 using namespace llvm::object;
 using namespace llvm::ELF;
 
-using namespace lld;
-using namespace lld::elf;
-
-SymbolTable *elf::symtab;
+namespace lld {
+namespace elf {
+SymbolTable *symtab;
 
 void SymbolTable::wrap(Symbol *sym, Symbol *real, Symbol *wrap) {
   // Swap symbols as instructed by -wrap.
   int &idx1 = symMap[CachedHashStringRef(sym->getName())];
   int &idx2 = symMap[CachedHashStringRef(real->getName())];
   int &idx3 = symMap[CachedHashStringRef(wrap->getName())];
 
   idx2 = idx1;
for (Symbol *sym : symVector)
     sym->parseSymbolVersion();
 
   // isPreemptible is false at this point. To correctly compute the binding of a
   // Defined (which is used by includeInDynsym()), we need to know if it is
   // VER_NDX_LOCAL or not. Compute symbol versions before handling
   // --dynamic-list.
   handleDynamicList();
 }
+
+} // namespace elf
+} // namespace lld

ELF/Symbols.h

 #include "InputFiles.h"
 #include "InputSection.h"
 #include "lld/Common/LLVM.h"
 #include "lld/Common/Strings.h"
 #include "llvm/Object/Archive.h"
 #include "llvm/Object/ELF.h"
 
 namespace lld {
+std::string toString(const elf::Symbol &);
+
+// There are two different ways to convert an Archive::Symbol to a string:
+// One for Microsoft name mangling and one for Itanium name mangling.
+// Call the functions toCOFFString and toELFString, not just toString.
+std::string toELFString(const llvm::object::Archive::Symbol &);
+
 namespace elf {
 class CommonSymbol;
 class Defined;
 class InputFile;
 class LazyArchive;
 class LazyObject;
 class SharedSymbol;
 class Symbol;
 class Undefined;
-} // namespace elf
-
-std::string toString(const elf::Symbol &);
-
-// There are two different ways to convert an Archive::Symbol to a string:
-// One for Microsoft name mangling and one for Itanium name mangling.
-// Call the functions toCOFFString and toELFString, not just toString.
-std::string toELFString(const elf::Archive::Symbol &);
-
-namespace elf {
 
 // This is a StringRef-like container that doesn't run strlen().
 //
 // ELF string tables contain a lot of null-terminated strings. Most of them
 // are not necessary for the linker because they are names of local symbols,
 // and the linker doesn't use local symbol names for name resolution. So, we
 // use this class to represents strings read from string tables.
 struct StringRefZ {

ELF/Symbols.cpp

 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Support/Path.h"
 #include <cstring>
 
 using namespace llvm;
 using namespace llvm::object;
 using namespace llvm::ELF;
 
-using namespace lld;
-using namespace lld::elf;
+namespace lld {
+// Returns a symbol for an error message.
+static std::string demangle(StringRef symName) {
+  if (elf::config->demangle)
+    return demangleItanium(symName);
+  return symName;
+}
 
+std::string toString(const elf::Symbol &b) { return demangle(b.getName()); }
+std::string toELFString(const Archive::Symbol &b) {
+  return demangle(b.getName());
+}
+
+namespace elf {
 Defined *ElfSym::bss;
 Defined *ElfSym::etext1;
 Defined *ElfSym::etext2;
 Defined *ElfSym::edata1;
 Defined *ElfSym::edata2;
 Defined *ElfSym::end1;
 Defined *ElfSym::end2;
 Defined *ElfSym::globalOffsetTable;
 Defined *ElfSym::mipsGp;
 Defined *ElfSym::mipsGpDisp;
 Defined *ElfSym::mipsLocalGp;
 Defined *ElfSym::relaIpltStart;
 Defined *ElfSym::relaIpltEnd;
 Defined *ElfSym::riscvGlobalPointer;
 Defined *ElfSym::tlsModuleBase;
 
-// Returns a symbol for an error message.
-static std::string demangle(StringRef symName) {
-  if (config->demangle)
-    return demangleItanium(symName);
-  return symName;
-}
-namespace lld {
-std::string toString(const Symbol &b) { return demangle(b.getName()); }
-std::string toELFString(const Archive::Symbol &b) {
-  return demangle(b.getName());
-}
-} // namespace lld
-
 static uint64_t getSymVA(const Symbol &sym, int64_t &addend) {
   switch (sym.kind()) {
   case Symbol::DefinedKind: {
     auto &d = cast<Defined>(sym);
     SectionBase *isec = d.section;
 
     // This is an absolute symbol.
     if (!isec)
bool Symbol::includeInDynsym() const {
   // safely drop weak undef symbols from .dynsym.
   if (isUndefWeak() && config->pie && sharedFiles.empty())
     return false;
 
   return isUndefined() || isShared() || exportDynamic || inDynamicList;
 }
 
 // Print out a log message for --trace-symbol.
-void elf::printTraceSymbol(const Symbol *sym) {
+void printTraceSymbol(const Symbol *sym) {
   std::string s;
   if (sym->isUndefined())
     s = ": reference to ";
   else if (sym->isLazy())
     s = ": lazy definition of ";
   else if (sym->isShared())
     s = ": shared definition of ";
   else if (sym->isCommon())
     s = ": common definition of ";
   else
     s = ": definition of ";
 
   message(toString(sym->file) + s + sym->getName());
 }
 
-void elf::maybeWarnUnorderableSymbol(const Symbol *sym) {
+void maybeWarnUnorderableSymbol(const Symbol *sym) {
   if (!config->warnSymbolOrdering)
     return;
 
   // If UnresolvedPolicy::Ignore is used, no "undefined symbol" error/warning
   // is emitted. It makes sense to not warn on undefined symbols.
   //
   // Note, ld.bfd --symbol-ordering-file= does not warn on undefined symbols,
   // but we don't have to be compatible here.
if (visibility == STV_DEFAULT && (isUndefined() || isLazy())) {
     // An undefined symbol with non default visibility must be satisfied
     // in the same DSO.
     uint8_t bind = binding;
     replace(other);
     binding = bind;
     referenced = true;
   }
 }
+
+} // namespace elf
+} // namespace lld

ELF/SyntheticSections.cpp

 #include <thread>
 
 using namespace llvm;
 using namespace llvm::dwarf;
 using namespace llvm::ELF;
 using namespace llvm::object;
 using namespace llvm::support;
 
-using namespace lld;
-using namespace lld::elf;
-
 using llvm::support::endian::read32le;
 using llvm::support::endian::write32le;
 using llvm::support::endian::write64le;
 
+namespace lld {
+namespace elf {
 constexpr size_t MergeNoTailSection::numShards;
 
 static uint64_t readUint(uint8_t *buf) {
   return config->is64 ? read64(buf) : read32(buf);
 }
 
 static void writeUint(uint8_t *buf, uint64_t val) {
   if (config->is64)
static ArrayRef<uint8_t> getVersion() {
   // +1 to include the terminating '\0'.
   return {(const uint8_t *)s.data(), s.size() + 1};
 }
 
 // Creates a .comment section containing LLD version info.
 // With this feature, you can identify LLD-generated binaries easily
 // by "readelf --string-dump .comment <file>".
 // The returned object is a mergeable string section.
-MergeInputSection *elf::createCommentSection() {
+MergeInputSection *createCommentSection() {
   return make<MergeInputSection>(SHF_MERGE | SHF_STRINGS, SHT_PROGBITS, 1,
                                  getVersion(), ".comment");
 }
 
 // .MIPS.abiflags section.
 template <class ELFT>
 MipsAbiFlagsSection<ELFT>::MipsAbiFlagsSection(Elf_Mips_ABIFlags flags)
     : SyntheticSection(SHF_ALLOC, SHT_MIPS_ABIFLAGS, 8, ".MIPS.abiflags"),
for (InputSectionBase *sec : inputSections) {
     flags.isa_rev = std::max(flags.isa_rev, s->isa_rev);
     flags.isa_ext = std::max(flags.isa_ext, s->isa_ext);
     flags.gpr_size = std::max(flags.gpr_size, s->gpr_size);
     flags.cpr1_size = std::max(flags.cpr1_size, s->cpr1_size);
     flags.cpr2_size = std::max(flags.cpr2_size, s->cpr2_size);
     flags.ases |= s->ases;
     flags.flags1 |= s->flags1;
     flags.flags2 |= s->flags2;
-    flags.fp_abi = elf::getMipsFpAbiFlag(flags.fp_abi, s->fp_abi, filename);
+    flags.fp_abi = getMipsFpAbiFlag(flags.fp_abi, s->fp_abi, filename);
   };
 
   if (create)
     return make<MipsAbiFlagsSection<ELFT>>(flags);
   return nullptr;
 }
 
 // .MIPS.options section.
for (InputSectionBase *sec : sections) {
     auto *r = reinterpret_cast<const Elf_Mips_RegInfo *>(sec->data().data());
     reginfo.ri_gprmask |= r->ri_gprmask;
     sec->getFile<ELFT>()->mipsGp0 = r->ri_gp_value;
   };
 
   return make<MipsReginfoSection<ELFT>>(reginfo);
 }
 
-InputSection *elf::createInterpSection() {
+InputSection *createInterpSection() {
   // StringSaver guarantees that the returned string ends with '\0'.
   StringRef s = saver.save(config->dynamicLinker);
   ArrayRef<uint8_t> contents = {(const uint8_t *)s.data(), s.size() + 1};
 
   return make<InputSection>(nullptr, SHF_ALLOC, SHT_PROGBITS, 1, contents,
                             ".interp");
 }
 
-Defined *elf::addSyntheticLocal(StringRef name, uint8_t type, uint64_t value,
-                                uint64_t size, InputSectionBase &section) {
+Defined *addSyntheticLocal(StringRef name, uint8_t type, uint64_t value,
   auto *s = make<Defined>(section.file, name, STB_LOCAL, STV_DEFAULT, type,
                           value, size, &section);
   if (in.symTab)
     in.symTab->addSymbol(s);
   return s;
 }
 
 static size_t getHashSize() {
static uint64_t addPltRelSz() {
   if (in.relaIplt->getParent() == in.relaPlt->getParent() &&
       in.relaIplt->name == in.relaPlt->name)
     size += in.relaIplt->getSize();
   return size;
 }
 
 // Add remaining entries to complete .dynamic contents.
 template <class ELFT> void DynamicSection<ELFT>::finalizeContents() {
-  elf::Partition &part = getPartition();
+  Partition &part = getPartition();
   bool isMain = part.name.empty();
 
   for (StringRef s : config->filterList)
     addInt(DT_FILTER, part.dynStrTab->addString(s));
   for (StringRef s : config->auxiliaryList)
     addInt(DT_AUXILIARY, part.dynStrTab->addString(s));
 
   if (!config->rpath.empty())
for (const SymbolTableEntry &s : getPartition().dynSymTab->getSymbols()) {
     buf += 2;
   }
 }
 
 bool VersionTableSection::isNeeded() const {
   return getPartition().verDef || getPartition().verNeed->isNeeded();
 }
 
-void elf::addVerneed(Symbol *ss) {
+void addVerneed(Symbol *ss) {
   auto &file = cast<SharedFile>(*ss->file);
   if (ss->verdefIndex == VER_NDX_GLOBAL) {
     ss->versionId = VER_NDX_GLOBAL;
     return;
   }
 
   if (file.vernauxs.empty())
     file.vernauxs.resize(file.verdefs.size());
void MergeNoTailSection::finalizeContents() {
   parallelForEach(sections, [&](MergeInputSection *sec) {
     for (size_t i = 0, e = sec->pieces.size(); i != e; ++i)
       if (sec->pieces[i].live)
         sec->pieces[i].outputOff +=
             shardOffsets[getShardId(sec->pieces[i].hash)];
   });
 }
 
-MergeSyntheticSection *elf::createMergeSynthetic(StringRef name, uint32_t type,
-                                                 uint64_t flags,
-                                                 uint32_t alignment) {
+MergeSyntheticSection *createMergeSynthetic(StringRef name, uint32_t type,
   bool shouldTailMerge = (flags & SHF_STRINGS) && config->optimize >= 2;
   if (shouldTailMerge)
     return make<MergeTailSection>(name, type, flags, alignment);
   return make<MergeNoTailSection>(name, type, flags, alignment);
 }
 
-template <class ELFT> void elf::splitSections() {
+template <class ELFT> void splitSections() {
   // splitIntoPieces needs to be called on each MergeInputSection
   // before calling finalizeContents().
   parallelForEach(inputSections, [](InputSectionBase *sec) {
     if (auto *s = dyn_cast<MergeInputSection>(sec))
       s->splitIntoPieces();
     else if (auto *eh = dyn_cast<EhInputSection>(sec))
       eh->split<ELFT>();
   });
for (InputFile *file : makeArrayRef(objectFiles).slice(1))
       if (file->abiVersion != ver)
         error("incompatible ABI version: " + toString(file));
     return ver;
   }
 
   return 0;
 }
 
-template <typename ELFT> void elf::writeEhdr(uint8_t *buf, Partition &part) {
+template <typename ELFT> void writeEhdr(uint8_t *buf, Partition &part) {
   // For executable segments, the trap instructions are written before writing
   // the header. Setting Elf header bytes to zero ensures that any unused bytes
   // in header are zero-cleared, instead of having trap instructions.
   memset(buf, 0, sizeof(typename ELFT::Ehdr));
   memcpy(buf, "\177ELF", 4);
 
   auto *eHdr = reinterpret_cast<typename ELFT::Ehdr *>(buf);
   eHdr->e_ident[EI_CLASS] = config->is64 ? ELFCLASS64 : ELFCLASS32;
template <typename ELFT> void writeEhdr(uint8_t *buf, Partition &part) {
   eHdr->e_shentsize = sizeof(typename ELFT::Shdr);
 
   if (!config->relocatable) {
     eHdr->e_phoff = sizeof(typename ELFT::Ehdr);
     eHdr->e_phentsize = sizeof(typename ELFT::Phdr);
   }
 }
 
-template <typename ELFT> void elf::writePhdrs(uint8_t *buf, Partition &part) {
+template <typename ELFT> void writePhdrs(uint8_t *buf, Partition &part) {
   // Write the program header table.
   auto *hBuf = reinterpret_cast<typename ELFT::Phdr *>(buf);
   for (PhdrEntry *p : part.phdrs) {
     hBuf->p_type = p->p_type;
     hBuf->p_flags = p->p_flags;
     hBuf->p_offset = p->p_offset;
     hBuf->p_vaddr = p->p_vaddr;
     hBuf->p_paddr = p->p_paddr;
SyntheticSection *next =
         i == partitions.size() - 1 ? in.partEnd : partitions[i + 1].elfHeader;
     write32(buf + 8, next->getVA() - partitions[i].elfHeader->getVA());
 
     va += 12;
     buf += 12;
   }
 }
 
-InStruct elf::in;
+InStruct in;
 
-std::vector<Partition> elf::partitions;
-Partition *elf::mainPart;
+std::vector<Partition> partitions;
+Partition *mainPart;
 
 template GdbIndexSection *GdbIndexSection::create<ELF32LE>();
 template GdbIndexSection *GdbIndexSection::create<ELF32BE>();
 template GdbIndexSection *GdbIndexSection::create<ELF64LE>();
 template GdbIndexSection *GdbIndexSection::create<ELF64BE>();
 
-template void elf::splitSections<ELF32LE>();
-template void elf::splitSections<ELF32BE>();
-template void elf::splitSections<ELF64LE>();
-template void elf::splitSections<ELF64BE>();
+template void splitSections<ELF32LE>();
+template void splitSections<ELF32BE>();
+template void splitSections<ELF64LE>();
+template void splitSections<ELF64BE>();
 
 template void PltSection::addEntry<ELF32LE>(Symbol &Sym);
 template void PltSection::addEntry<ELF32BE>(Symbol &Sym);
 template void PltSection::addEntry<ELF64LE>(Symbol &Sym);
 template void PltSection::addEntry<ELF64BE>(Symbol &Sym);
 
-template class elf::MipsAbiFlagsSection<ELF32LE>;
-template class elf::MipsAbiFlagsSection<ELF32BE>;
-template class elf::MipsAbiFlagsSection<ELF64LE>;
-template class elf::MipsAbiFlagsSection<ELF64BE>;
-
-template class elf::MipsOptionsSection<ELF32LE>;
-template class elf::MipsOptionsSection<ELF32BE>;
-template class elf::MipsOptionsSection<ELF64LE>;
-template class elf::MipsOptionsSection<ELF64BE>;
-
-template class elf::MipsReginfoSection<ELF32LE>;
-template class elf::MipsReginfoSection<ELF32BE>;
-template class elf::MipsReginfoSection<ELF64LE>;
-template class elf::MipsReginfoSection<ELF64BE>;
-
-template class elf::DynamicSection<ELF32LE>;
-template class elf::DynamicSection<ELF32BE>;
-template class elf::DynamicSection<ELF64LE>;
-template class elf::DynamicSection<ELF64BE>;
-
-template class elf::RelocationSection<ELF32LE>;
-template class elf::RelocationSection<ELF32BE>;
-template class elf::RelocationSection<ELF64LE>;
-template class elf::RelocationSection<ELF64BE>;
-
-template class elf::AndroidPackedRelocationSection<ELF32LE>;
-template class elf::AndroidPackedRelocationSection<ELF32BE>;
-template class elf::AndroidPackedRelocationSection<ELF64LE>;
-template class elf::AndroidPackedRelocationSection<ELF64BE>;
-
-template class elf::RelrSection<ELF32LE>;
-template class elf::RelrSection<ELF32BE>;
-template class elf::RelrSection<ELF64LE>;
-template class elf::RelrSection<ELF64BE>;
-
-template class elf::SymbolTableSection<ELF32LE>;
-template class elf::SymbolTableSection<ELF32BE>;
-template class elf::SymbolTableSection<ELF64LE>;
-template class elf::SymbolTableSection<ELF64BE>;
-
-template class elf::VersionNeedSection<ELF32LE>;
-template class elf::VersionNeedSection<ELF32BE>;
-template class elf::VersionNeedSection<ELF64LE>;
-template class elf::VersionNeedSection<ELF64BE>;
-
-template void elf::writeEhdr<ELF32LE>(uint8_t *Buf, Partition &Part);
-template void elf::writeEhdr<ELF32BE>(uint8_t *Buf, Partition &Part);
-template void elf::writeEhdr<ELF64LE>(uint8_t *Buf, Partition &Part);
-template void elf::writeEhdr<ELF64BE>(uint8_t *Buf, Partition &Part);
-
-template void elf::writePhdrs<ELF32LE>(uint8_t *Buf, Partition &Part);
-template void elf::writePhdrs<ELF32BE>(uint8_t *Buf, Partition &Part);
-template void elf::writePhdrs<ELF64LE>(uint8_t *Buf, Partition &Part);
-template void elf::writePhdrs<ELF64BE>(uint8_t *Buf, Partition &Part);
-
-template class elf::PartitionElfHeaderSection<ELF32LE>;
-template class elf::PartitionElfHeaderSection<ELF32BE>;
-template class elf::PartitionElfHeaderSection<ELF64LE>;
-template class elf::PartitionElfHeaderSection<ELF64BE>;
-
-template class elf::PartitionProgramHeadersSection<ELF32LE>;
-template class elf::PartitionProgramHeadersSection<ELF32BE>;
-template class elf::PartitionProgramHeadersSection<ELF64LE>;
-template class elf::PartitionProgramHeadersSection<ELF64BE>;
+template class MipsAbiFlagsSection<ELF32LE>;
+template class MipsAbiFlagsSection<ELF32BE>;
+template class MipsAbiFlagsSection<ELF64LE>;
+template class MipsAbiFlagsSection<ELF64BE>;
+
+template class MipsOptionsSection<ELF32LE>;
+template class MipsOptionsSection<ELF32BE>;
+template class MipsOptionsSection<ELF64LE>;
+template class MipsOptionsSection<ELF64BE>;
+
+template class MipsReginfoSection<ELF32LE>;
+template class MipsReginfoSection<ELF32BE>;
+template class MipsReginfoSection<ELF64LE>;
+template class MipsReginfoSection<ELF64BE>;
+
+template class DynamicSection<ELF32LE>;
+template class DynamicSection<ELF32BE>;
+template class DynamicSection<ELF64LE>;
+template class DynamicSection<ELF64BE>;
+
+template class RelocationSection<ELF32LE>;
+template class RelocationSection<ELF32BE>;
+template class RelocationSection<ELF64LE>;
+template class RelocationSection<ELF64BE>;
+
+template class AndroidPackedRelocationSection<ELF32LE>;
+template class AndroidPackedRelocationSection<ELF32BE>;
+template class AndroidPackedRelocationSection<ELF64LE>;
+template class AndroidPackedRelocationSection<ELF64BE>;
+
+template class RelrSection<ELF32LE>;
+template class RelrSection<ELF32BE>;
+template class RelrSection<ELF64LE>;
+template class RelrSection<ELF64BE>;
+
+template class SymbolTableSection<ELF32LE>;
+template class SymbolTableSection<ELF32BE>;
+template class SymbolTableSection<ELF64LE>;
+template class SymbolTableSection<ELF64BE>;
+
+template class VersionNeedSection<ELF32LE>;
+template class VersionNeedSection<ELF32BE>;
+template class VersionNeedSection<ELF64LE>;
+template class VersionNeedSection<ELF64BE>;
+
+template void writeEhdr<ELF32LE>(uint8_t *Buf, Partition &Part);
+template void writeEhdr<ELF32BE>(uint8_t *Buf, Partition &Part);
+template void writeEhdr<ELF64LE>(uint8_t *Buf, Partition &Part);
+template void writeEhdr<ELF64BE>(uint8_t *Buf, Partition &Part);
+
+template void writePhdrs<ELF32LE>(uint8_t *Buf, Partition &Part);
+template void writePhdrs<ELF32BE>(uint8_t *Buf, Partition &Part);
+template void writePhdrs<ELF64LE>(uint8_t *Buf, Partition &Part);
+template void writePhdrs<ELF64BE>(uint8_t *Buf, Partition &Part);
+
+template class PartitionElfHeaderSection<ELF32LE>;
+template class PartitionElfHeaderSection<ELF32BE>;
+template class PartitionElfHeaderSection<ELF64LE>;
+template class PartitionElfHeaderSection<ELF64BE>;
+
+template class PartitionProgramHeadersSection<ELF32LE>;
+template class PartitionProgramHeadersSection<ELF32BE>;
+template class PartitionProgramHeadersSection<ELF64LE>;
+template class PartitionProgramHeadersSection<ELF64BE>;
+
+} // namespace elf
+} // namespace lld

ELF/Target.cpp

 #include "SymbolTable.h"
 #include "Symbols.h"
 #include "lld/Common/ErrorHandler.h"
 #include "llvm/Object/ELF.h"
 
 using namespace llvm;
 using namespace llvm::object;
 using namespace llvm::ELF;
-using namespace lld;
-using namespace lld::elf;
 
-const TargetInfo *elf::target;
-
-std::string lld::toString(RelType type) {
+namespace lld {
+std::string toString(elf::RelType type) {
   StringRef s = getELFRelocationTypeName(elf::config->emachine, type);
   if (s == "Unknown")
     return ("Unknown (" + Twine(type) + ")").str();
   return s;
 }
 
-TargetInfo *elf::getTarget() {
+namespace elf {
+const TargetInfo *target;
+
+TargetInfo *getTarget() {
   switch (config->emachine) {
   case EM_386:
   case EM_IAMCU:
     return getX86TargetInfo();
   case EM_AARCH64:
     return getAArch64TargetInfo();
   case EM_AMDGPU:
     return getAMDGPUTargetInfo();
for (InputSectionBase *d : inputSections) {
 
     uint8_t *isecLoc = Out::bufferStart + isec->getParent()->offset + isec->outSecOff;
     if (isecLoc <= loc && loc < isecLoc + isec->getSize())
       return {isec, isec->template getLocation<ELFT>(loc - isecLoc) + ": "};
   }
   return {};
 }
 
-ErrorPlace elf::getErrorPlace(const uint8_t *loc) {
+ErrorPlace getErrorPlace(const uint8_t *loc) {
   switch (config->ekind) {
   case ELF32LEKind:
     return getErrPlace<ELF32LE>(loc);
   case ELF32BEKind:
     return getErrPlace<ELF32BE>(loc);
   case ELF64LEKind:
     return getErrPlace<ELF64LE>(loc);
   case ELF64BEKind:

 }
 
 uint64_t TargetInfo::getImageBase() const {
   // Use -image-base if set. Fall back to the target default if not.
   if (config->imageBase)
     return *config->imageBase;
   return config->isPic ? 0 : defaultImageBase;
 }
+
+} // namespace elf
+} // namespace lld

ELF/Writer.cpp

 #include <climits>
 
 using namespace llvm;
 using namespace llvm::ELF;
 using namespace llvm::object;
 using namespace llvm::support;
 using namespace llvm::support::endian;
 
-using namespace lld;
-using namespace lld::elf;
-
+namespace lld {
+namespace elf {
 namespace {
 // The writer writes a SymbolTable result to a file.
 template <class ELFT> class Writer {
 public:
   Writer() : buffer(errorHandler().outputBuffer) {}
   using Elf_Shdr = typename ELFT::Shdr;
   using Elf_Ehdr = typename ELFT::Ehdr;
   using Elf_Phdr = typename ELFT::Phdr;
private:
   uint64_t sectionHeaderOff;
 };
 } // anonymous namespace
 
 static bool isSectionPrefix(StringRef prefix, StringRef name) {
   return name.startswith(prefix) || name == prefix.drop_back();
 }
 
-StringRef elf::getOutputSectionName(const InputSectionBase *s) {
+StringRef getOutputSectionName(const InputSectionBase *s) {
   if (config->relocatable)
     return s->name;
 
   // This is for --emit-relocs. If .text.foo is emitted as .text.bar, we want
   // to emit .rela.text.foo as .rela.text.bar for consistency (this is not
   // technically required, but not doing it is odd). This code guarantees that.
   if (auto *isec = dyn_cast<InputSection>(s)) {
     if (InputSectionBase *rel = isec->getRelocatedSection()) {
StringRef getOutputSectionName(const InputSectionBase *s) {
   return s->name;
 }
 
 static bool needsInterpSection() {
   return !sharedFiles.empty() && !config->dynamicLinker.empty() &&
          script->needsInterpSection();
 }
 
-template <class ELFT> void elf::writeResult() { Writer<ELFT>().run(); }
+template <class ELFT> void writeResult() { Writer<ELFT>().run(); }
 
 static void removeEmptyPTLoad(std::vector<PhdrEntry *> &phdrs) {
   llvm::erase_if(phdrs, [&](const PhdrEntry *p) {
     if (p->p_type != PT_LOAD)
       return false;
     if (!p->firstSec)
       return true;
     uint64_t size = p->lastSec->addr + p->lastSec->size - p->firstSec->addr;
     return size == 0;
   });
 }
 
-void elf::copySectionsIntoPartitions() {
+void copySectionsIntoPartitions() {
   std::vector<InputSectionBase *> newSections;
   for (unsigned part = 2; part != partitions.size() + 1; ++part) {
     for (InputSectionBase *s : inputSections) {
       if (!(s->flags & SHF_ALLOC) || !s->isLive())
         continue;
       InputSectionBase *copy;
       if (s->type == SHT_NOTE)
         copy = make<InputSection>(cast<InputSection>(*s));
       else if (auto *es = dyn_cast<EhInputSection>(s))
         copy = make<EhInputSection>(*es);
       else
         continue;
       copy->partition = part;
       newSections.push_back(copy);
     }
   }
 
   inputSections.insert(inputSections.end(), newSections.begin(),
                        newSections.end());
 }
 
-void elf::combineEhSections() {
+void combineEhSections() {
   for (InputSectionBase *&s : inputSections) {
     // Ignore dead sections and the partition end marker (.part.end),
     // whose partition number is out of bounds.
     if (!s->isLive() || s->partition == 255)
       continue;
 
     Partition &part = s->getPartition();
     if (auto *es = dyn_cast<EhInputSection>(s)) {

 static Defined *addAbsolute(StringRef name) {
   Symbol *sym = symtab->addSymbol(Defined{nullptr, name, STB_GLOBAL, STV_HIDDEN,
                                           STT_NOTYPE, 0, 0, nullptr});
   return cast<Defined>(sym);
 }
 
 // The linker is expected to define some symbols depending on
 // the linking result. This function defines such symbols.
-void elf::addReservedSymbols() {
+void addReservedSymbols() {
   if (config->emachine == EM_MIPS) {
     // Define _gp for MIPS. st_value of _gp symbol will be updated by Writer
     // so that it points to an absolute address which by default is relative
     // to GOT. Default offset is 0x7ff0.
     // See "Global Data Symbols" in Chapter 6 in the following document:
     // ftp://www.linux-mips.org/pub/linux/mips/doc/ABI/mipsabi.pdf
     ElfSym::mipsGp = addAbsolute("_gp");
 

 static OutputSection *findSection(StringRef name, unsigned partition = 1) {
   for (BaseCommand *base : script->sectionCommands)
     if (auto *sec = dyn_cast<OutputSection>(base))
       if (sec->name == name && sec->partition == partition)
         return sec;
   return nullptr;
 }
 
-template <class ELFT> void elf::createSyntheticSections() {
+template <class ELFT> void createSyntheticSections() {
   // Initialize all pointers with NULL. This is needed because
   // you can call lld::elf::main more than once as a library.
   memset(&Out::first, 0, sizeof(Out));
 
   // Add the .interp section first because it is not a SyntheticSection.
   // The removeUnusedSyntheticSections() function relies on the
   // SyntheticSections coming last.
   if (needsInterpSection()) {
case BuildIdKind::Uuid:
     break;
   default:
     llvm_unreachable("unknown BuildIdKind");
   }
   for (Partition &part : partitions)
     part.buildId->writeBuildId(buildId);
 }
 
-template void elf::createSyntheticSections<ELF32LE>();
-template void elf::createSyntheticSections<ELF32BE>();
-template void elf::createSyntheticSections<ELF64LE>();
-template void elf::createSyntheticSections<ELF64BE>();
-
-template void elf::writeResult<ELF32LE>();
-template void elf::writeResult<ELF32BE>();
-template void elf::writeResult<ELF64LE>();
-template void elf::writeResult<ELF64BE>();
+template void createSyntheticSections<ELF32LE>();
+template void createSyntheticSections<ELF32BE>();
+template void createSyntheticSections<ELF64LE>();
+template void createSyntheticSections<ELF64BE>();
+
+template void writeResult<ELF32LE>();
+template void writeResult<ELF32BE>();
+template void writeResult<ELF64LE>();
+template void writeResult<ELF64BE>();
+
+} // namespace elf
+} // namespace lld